IRP for Tire Retreading and Tire Repairing

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TRMGTRMG Tread Rubber and Tire Repair Materials Manufacturers’ Group INDUSTRY RECOMMENDED PRACTICES FOR TIRE RETREADING AND TIRE REPAIRING

Issued August 15, 1997 Revised May 27, 2020 I INTRODUCTION

The tire retread and repair industry serves a Questions pertaining to a specific product or piece vital purpose in the recycling of worn tires. of service equipment should be addressed to the Through recycling, valuable natural resources are manufacturer of that product. conserved and the economic function of tires is prolonged. To enhance public and industry safety The Federal Government publications listed in the and efficiency in the retreading and repairing of Table of Contents under "Reference Documents" radial passenger car, light truck radial fabric body are listed only for ease of reference in conjunction ply, light truck radial steel body ply, medium truck, with these IRPs. They may be obtained from the heavy radial truck, bus, and bias tires, the Tread appropriate government agency and/or the U.S. Rubber and Tire Repair Materials Manufacturers’ Government Printing Office. Group (TRMG), taking into account the views of interested members of affected industries and the While the Tire Retread and Repair Information public, has drafted and periodically updates this Bureau (TRIB) and the Tire Industry Association set of Industry Recommended Practices for Tire (TIA) did not participate in the technical discussions Retreading and Tire Repairing (IRPs). leading to the preparation of this document, TRIB and TIA have been designated as the primary agents for The IRPs are completely voluntary. Neither the distribution and general dissemination of the IRPs. TRMG, or other associations or companies, have Any comments or suggestions may be submitted to agreed to use the IRPs, or to make adoption of or TRIB or TIA, and additional digital copies of the IRPs adherence to the IRPs, a condition of membership. may be obtained from TRIB or TIA at: Nor does the TRMG or other associations seek to inspect and/or accredit the operations of industry Tire Retread and Repair Information Bureau members or enforce compliance with the IRPs. 703-533-7677 www.retread.org No member of the industry or other person is Email: [email protected] authorized to use these IRPs to advertise, promote, induce or disparage the sale of retreaded and/or Tire Industry Association repaired tires or of tire retreading or repairing 800-876-8372 services. www.tireindustry.org Much as the TRMG would like to do so, there is no way to come up with warnings and cautions in these © 1977 – 2020. All rights reserved. Unauthorized IRPs that will cover every eventuality. The IRPs do reproduction and/or distribution is prohibited by not, for example, eliminate the need for in-depth, law and international treaties and will be vigorously hands-on training of industry personnel in such enforced. areas as mounting/demounting, tire balancing, and retreading/repairing. Personnel performing these services should be professionally trained by persons qualified to conduct that training.

II TRMG, TRIB and TIA disclaim any and all liability for any personal injury, property or other damages whatsoever, whether direct, indirect, special, consequential or otherwise, resulting from any use of or reliance upon the IRPs or any information contained in the IRPs by any person or entity. Neither TRMG, TRIB, TIA or any of their officers, directors, employees, members, agents or affiliates make any guarantee, representation or warranty, either express or implied, with respect to the accuracy, completeness, usefulness or suitability of the IRPs or any of the information contained in the IRPs. These IRPs are provided for educational purposes only. In issues and making the IRPs available, TRMG, TRIB and TIA are not undertaking to render professional or other services or advice for or on behalf of any person or entity. Nor is TRMG, TRIB or TIA undertaking to perform or assuming any duty owed by any person or entity to any other person or entity. Anyone using these IRPs or any portion thereof should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable care and judgment in any circumstances. Users of the IRPs or any portion thereof should consult applicable federal, state, and local laws and regulations. TRMG, TRIB and TIA do not, by publication of the IRPs or any of the information contained in the IRPs, intend to promote, suggest or encourage any action that is not in compliance with any applicable laws, and the IRPs shall not be construed as doing so.

III NAVIGATING THROUGH THE IRPs The following charts show the size guidelines for light truck, medium truck, and heavy truck tires. Retreaders are encouraged to use this chart as a guide for determining which section of the IRPs to refer to when retreading or repairing a tire. In addition to providing size guidelines, the chart is color coded to correspond to the various sections of the IRPs.

RADIAL LIGHT TRUCK TIRE SIZE CHART RETREADING REPAIRING RETREADING REPAIRING Fabric Light Truck Fabric Light Truck Steel* Body Ply Steel* Body Ply (Up to Load Range E) (Up to Load Range E) Light Truck Light Truck *or similar material *or similar material 6.50 – 12.50 6.50 – 12.50 215/85 – 255/85 215/85 – 255/85 (Load Range E and above) (Load Range E and above) 225/75R16 – 245/75R17 225/75R16 – 245/75R17 215/75 – 265/75 215/75 – 265/75

MEDIUM AND HEAVY RADIAL TRUCK TIRE SIZE CHART RETREADING REPAIRING Medium Truck Heavy Radial Truck Medium Truck Heavy Radial Truck 7.50 – 10.00 11.00- 16.00 7.50 – 10.00 11.00- 16.00 8 – 11 12 – 18 8 – 11 12 – 18 215/75 – 285/75 295/80 – 445/65 215/75 – 285/75 295/80 – 445/65 435/50 - 495/50 435/50 - 495/50

NOTE: Dimensions shown are for general guidance. Repair material manufacturers’ and new tire manufacturers’ recommendations may differ. Specific limits should be based on recommendations of the tire manufacturer, repair material manufacturer, and type of tire service. Consult tire manufacturer and repair material manufacturer for tire sizes not covered.

IV Table of Contents

RETREADING RADIAL PASSENGER CAR AND LIGHT TRUCK RADIAL FABRIC BODY PLY TIRES I. PURPOSE �� 1 II. SCOPE �� 1 III. INDUSTRY TERMINOLOGY �� 1 IV. INITIAL CASING INSPECTION AND SELECTION FOR RETREADING �� 1 A. General Statement ��1 B. Radial Passenger Car Tire Casings ��2 C. Inspection Criteria for Radial Passenger Car Tire Casings Used on the Highway ��2 D. Inspection Criteria for Light Truck Radial Fabric Body Ply Tire Casings Used on the Highway �� 3 E. Selection Criteria for Light Truck Radial Fabric Body Ply Tire Casings to be Retreaded for Use in Steer Axle Applications �� 3 V. PROCESSING ��4 A. General Statement �� 4 B. Buffing �� 4 C. Cementing (if required) �� 4 D. Building/Tread Application �� 4 E. Curing ��5 VI. FINAL INSPECTION ��6

REPAIRING RADIAL PASSENGER CAR AND LIGHT TRUCK RADIAL FABRIC BODY PLY TIRES I. PURPOSE �� 7 II. SCOPE �� 7 III. INDUSTRY TERMINOLOGY �� 7 IV. GENERAL STATEMENT ABOUT TIRE REPAIRING �� 7 V. INITIAL TIRE INSPECTION ��8 A. Inspection Criteria for Tire Repairing �� 8 VI. MINOR RUBBER REPAIRS ��9 A. Spot Repair �� 9 B. Inner Liner Repair �� 9 C. Bead Area Repair �� 9 D. Steps for Minor Rubber Repair �� 9 VII. PUNCTURE REPAIR (NAIL HOLE REPAIR) ��10 A. Radial Passenger Car and Light Truck Radial Fabric Body Ply Tire Puncture Repair ��11 B. Steps for Puncture Repair ��11 VIII. REINFORCEMENT REPAIRS ��16 A. Steps for Reinforcement Repairs �� 16 IX. SECTION REPAIRS ��16

V Table of Contents

A. Section Repair Limits �� 16 B. Steps for Section Repairs ��17 X. REPAIR FINISHING ��19 A. General Repair Finishing �� 19 B. Steps for Repair Finishing �� 19 XI. FINAL REPAIR INSPECTION ��19 A. General Repair Inspection �� 19 B. Criteria for Repair Inspection �� 19

RETREADING LIGHT TRUCK RADIAL STEEL BODY PLY TIRES LOAD RANGE E AND ABOVE I. PURPOSE ��20 II. SCOPE ��20 III. INDUSTRY TERMINOLOGY ��20 IV. INITIAL CASING INSPECTION AND SELECTION FOR RETREADING ��20 A. General Statement �� 20 B. Inspection Criteria for Light Truck Radial Steel Body Ply Tire Casings Used on the Highway ��21 C. Selection Criteria for Light Truck Radial Steel Body Ply Tire Casings to be Retreaded for Use in Steer Axle Applications ��22 V. PROCESSING �� 22 A. General Statement ��22 B. Buffing ��22 C. Cementing (if required) �� 22 D. Building/Tread Application �� 23 E. Curing �� 23 VI. FINAL INSPECTION ��24

REPAIRING LIGHT TRUCK RADIAL STEEL BODY PLY TIRES LOAD RANGE E AND ABOVE I. PURPOSE ��25 II. SCOPE ��25 III. INDUSTRY TERMINOLOGY ��25 IV. GENERAL STATEMENT ABOUT TIRE REPAIRING ��25 V. INITIAL TIRE INSPECTION ��26 A. Inspection Criteria for Repairing �� 26 VI. MINOR RUBBER REPAIRS �� 27 A. Spot Repair ��27 B. Inner Liner Repair ��27 C. Bead Area Repair ��27 D. Steps for Minor Rubber Repair ��27 VII. PUNCTURE REPAIR (NAIL HOLE REPAIR) ��28

VI Table of Contents

A. Light Truck Radial Steel Body Ply Tire Puncture Repair �� 29 B. Steps for Puncture Repair �� 29 VIII. REINFORCEMENT REPAIRS ��34 A. Steps for Reinforcement Repairs �� 34 IX. SECTION REPAIRS ��34 A. Section Repair Limits �� 34 B. Steps for Section Repairs �� 35 X. REPAIR FINISHING �� 37 A. General Repair Finishing ��37 B. Steps for Repair Finishing ��37 XI. FINAL REPAIR INSPECTION �� 37 A. General Repair Inspection ��37 B. Criteria for Repair Inspection ��37

RETREADING MEDIUM TRUCK, HEAVY RADIAL TRUCK, AND BUS TIRES I. PURPOSE ��38 II. SCOPE ��38 III. INDUSTRY TERMINOLOGY ��38 IV. INITIAL CASING INSPECTION AND SELECTION FOR RETREADING ��38 A. General Statement �� 38 B. Inspection Criteria for Medium Truck, Heavy Radial Truck, and Bus Casings Used on the Highway �� 39 C. Selection Criteria for Medium Truck, Heavy Radial Truck, and Bus Tire Casings to be Retreaded for Use in Steer Axle Applications �� 40 D. Zipper Damage Indicators �� 40 V. PROCESSING ��40 A. General Statement �� 40 B. Buffing ��41 C. Cementing (if required) ��41 D. Building/Tread Application ��42 E. Curing �� 44 VI. FINAL INSPECTION ��44

REPAIRING MEDIUM TRUCK, HEAVY RADIAL TRUCK, AND BUS TIRES I. PURPOSE ��46 II. SCOPE ��46 III. INDUSTRY TERMINOLOGY ��46 IV. GENERAL STATEMENT ABOUT TIRE REPAIRING ��46 V. INITIAL TIRE INSPECTION �� 47

VII Table of Contents

A. Inspection Criteria for Repairing ��47 B. Zipper Damage Indicators �� 48 VI. MINOR RUBBER REPAIRS ��48 A. Spot Repair �� 48 B. Inner Liner Repair �� 48 C. Bead Area Repair �� 48 D. Steps for Minor Rubber Repairs �� 49 VII. PUNCTURE REPAIR (NAIL HOLE REPAIR) ��50 A. Medium Truck, Heavy Radial Truck, and Bus Tire Puncture Repair �� 50 B. Steps for Puncture Repair ��51 VIII. REINFORCED SHOULDER REPAIR ��55 A. Reinforced Shoulder Repair (RSR) Unit Placement ��55 B. Benefit of Offsetting a Repair Unit (non-centered) ��55 SUMMARY - REINFORCED SHOULDER REPAIRS �� 55 IX. REINFORCEMENT REPAIRS ��56 A. Reinforcement Repair Limits �� 56 B. Steps for Reinforcement Repairs �� 56 X. SECTION REPAIRS ��56 A. Section Repair Limits �� 56 B. Steps for Section Repairs �� 56 XI. REPAIR FINISHING ��60 A. General Repair Finishing �� 60 B. Steps for Repair Finishing ��61 XII. FINAL REPAIR INSPECTION �� 61 A. General Repair Inspection ��61 B. Criteria for Repair Inspection ��61

TABLES Table I - Non-Repairable Bead Area for Body Ply Damage...... 63 Table II - Maximum Section Repair Limits for Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires...... 63 Table II-A - Maximum Section Repair Limits for Radial Truck Tires...... 64

APPENDICES Appendix I – Common Retread and Repair Terminology – A Compendium of Industry Terms...... 66 Appendix 2 – Radial Truck Tire Diagrams...... 80 Appendix 3 – Measuring Injuries in Radial Tires...... 82 Appendix 4 – Repairable Areas in Radial Tires...... 83 Appendix 5 – Sidewall Labeling...... 84 Appendix 6 – Reinforced Shoulder Repair Unit Placement...... 86

VIII Table of Contents

REFERENCE DOCUMENTS 1. National Highway Traffic Safety Administration, Federal Motor Vehicle Safety Standard No. 117, Retreaded Pneumatic Tires 49 C F R § 571 117 as amended (FMVSS 117) 2. National Highway Traffic Safety Administration, Tire Identification and Record Keeping, 49 C.F.R. Part 574, as amended

IX Light Truck Radial Fabric Body Ply Tires Radial Passenger Car and RETREADING

Industry Recommended Practices for Tire Retreading Retreading Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires

Contents Page III. INDUSTRY TERMINOLOGY

I. PURPOSE...... 1 See Appendix 1 - Common Retread and Repair II. SCOPE...... 1 Terminology - A Compendium of Industry Terms. III. INDUSTRY TERMINOLOGY...... 1 IV. INITIAL CASING INSPECTION AND SELECTION FOR RETREADING...... 1 IV. INITIAL CASING INSPECTION AND V. PROCESSING...... 4 SELECTION FOR RETREADING VI. FINAL INSPECTION...... 6 A. General Statement Thorough inspection should be made by a I. PURPOSE skilled operator and should include placing the tire casing on a tire inspection machine, The purpose of this section is to offer Industry or other machine capable of spreading the Recommended Practices (IRPs) to members of beads under adequate lighting (i.e., 200 the industry, for the manufacturing of retreaded footcandles (fc) / 2153 lux (lx) minimum, radial passenger car and light truck radial fabric 300 fc / 3229 lx recommended) at the work body ply tires, for highway service. These IRPs surface, so that the interior and exterior of are not intended to be, and should not be, used the casing is adequately exposed for visual as a substitute for the judgment that each and manual examination. industry member should make in establishing and implementing procedures, training, and supervisory practices for the proper inspection, selection, and retreading of worn tires. CAUTION

Before beginning, retreaders should contact tire manufacturers regarding proper procedures and guidelines for retreading radial passenger car and light truck radial fabric body ply tires. Tire Casing on Inspection Machine

II. SCOPE All casings should be dry and free of all This section addresses industry terminology, initial loose contaminants (e.g., dirt, water, debris, casing inspection and selection for retreading, sealants, visual materials, balancing materials, processing, and final inspection guidelines used etc.) and/or other foreign materials, prior to in the tire retreading industry. inspection. All repair units should be replaced

1 Light Truck Radial Fabric Body Ply Tires Retreading Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Radial Passenger Car and unless they can be determined to be sound g. Circumferential cracking

and have been properly installed. Inspection RETREADING criteria should be posted in retread plants. h. Broken, damaged, kinked or exposed bead wire bundle Retreaders should consult new tire manufacturers or material manufacturers i. Damaged beads exposing bead regarding the alteration (i.e., retreading or wire or cord fabric repairing) of speed rated tires. j. Improper labeling In addition to visual inspection, it is also recommended that some type of k. Tire belt separation or lifting nondestructive inspection equipment (e.g., holography, shearography, X-ray, ultrasonics, l. Tread separations which are not electrostatic, high pressure tester, etc.) be removed during buffing utilized for casing inspection. m. Radial tires with rust or corrosion beyond repairable limits B. Radial Passenger Car Tire Casings n. Any signs of weakness or non- Radial passenger car tire casings must meet the repairable injury (e.g., softness requirements of Federal Motor Vehicle Safety due to contamination from Standard 117, Retreaded Pneumatic Tires, 49 chemical/petroleum products, C.F.R. § 571.117, as amended (FMVSS 117). ripples, bulges, porosity, etc.) in the sidewall, particularly in the upper sidewall C. Inspection Criteria for Radial Passenger Car Tire Casings Used on the Highway 2. Internal No radial passenger car tire casings should a. Flex breaks, X-breaks or impact be accepted for retreading having any of the breaks following conditions or injuries which require repairs beyond the limits of the IRPs, or repairs in b. Porous, contaminated from chemical the area described in Table I (see Tables section degradation, or loose inner liners at the end of this document). c. Open inner liner splices which 1. External expose cord a. Exposed fabric in the tread area in d. Loose cords on the inside ply excess of FMVSS 117 or evidence of having been run underinflated or overloaded b. Ply separation e. Injury to the ply cord fabric in the c. Broken belts bead area and sidewall d. Excessive oxidation (i.e., weather f. Previously installed repairs found to checking) extending to the body be defective and/or unrepairable plies or deeper than 2/32” (1.5 mm) g. Casings having or requiring any e. Surface cuts which exceed the section repairs size of a repairable injury and penetrate the cord body h. Damage larger than allowable repair limits f. Radial ply cracking

2 Light Truck Radial Fabric Body Ply Tires Retreading Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Radial Passenger Car and D. Inspection Criteria for Light Truck c. Flex breaks, X-breaks or impact Radial Fabric Body Ply Tire Casings breaks RETREADING Used on the Highway d. Loose cords on the inside ply No light truck radial fabric body ply tire casings or evidence of having been run should be accepted for retreading having any underinflated or overloaded of the following conditions or injuries which require repairs beyond the limits of the IRPs or e. Non-repairable damage to the beyond the limits outlined in Tables I and II (see inner liner or bead area on tires Tables section at the end of this document). identified as tubeless

1. External f. Porous, contaminated from chemical degradation, or loose inner liners a. Ply separation beyond repairable limits g. Previously installed repairs found to be defective and unrepairable b. Tread separations which cannot be removed during buffing h. Suspected of potential zipper damage c. Broken, damaged, kinked or exposed bead wire bundle • Cuts, snags or chips exposing body cords d. Excessive oxidation (i.e., weather checking) extending to the body • Distortions or undulations (i.e., plies or deeper than 2/32’’ (1.5 mm) ripples and/or bulges) visible when using an indirect light e. Circumferential cracking source which will produce shadows left by any sidewall f. Any signs of weakness or non- irregularities repairable injury (e.g., softness due to contamination from • Creasing, wrinkling, cracking or chemical/petroleum products, discoloration of the inner liner ripples, bulges, porosity, etc.) in the sidewall, particularly in the upper • Soft spot(s) in the sidewall flex sidewall area g. Crunching or popping sounds • Protruding filaments indicating when flexed broken cords h. Surface cuts which exceed the • Any popping sound when size of a repairable injury and feeling for soft spots or when penetrate the cord body rolling the tire i. Radial cracking E. Selection Criteria for Light Truck j. Improper labeling Radial Fabric Body Ply Tire Casings to be Retreaded for Use in Steer Axle 2. Internal Applications a. Injuries to the body plies in the Light truck radial fabric body ply tire casings non-repairable bead area retreaded for steer axle applications, should be appropriately marked on the sidewall b. Open inner liner splices which adjacent to the federal retread identification expose cord

3 Light Truck Radial Fabric Body Ply Tires Retreading Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Radial Passenger Car and code (see Appendix 5 for federally-required labeling). Note that certain state and/or WARNING RETREADING other government agencies may have specific requirements. DO NOT use flammable cement near fire, flame or any other source of ignition. Explosive force and/or fire from ignition of cement could cause V. PROCESSING serious personal injury or death. A. General Statement

The processes listed below are essential C. Cementing (if required) to proper manufacturing of the retread and should be posted in retread plants. 1. Tires to be cemented should be free of Adequate lighting (i.e., 200 fc / 2153 lx loose cords or foreign material such as minimum, 300 fc / 3229 lx recommended) rubber buffings, dirt, oil, etc. at the work surface should be provided in the processing area. 2. Cementing should be accomplished as soon as possible. Consult the retread materials supplier for additional B. Buffing information. 1. Buffed tire dimensions should be 3. Exposed steel should be cemented as appropriate to the tire brand, size, soon as possible - recommendation is and type, as well as to the retread within 15 minutes after exposure. system used. After buffing, wait time to build should be minimized in order 4. Cemented tires should be kept free to avoid contamination or oxidation. from dust and other contaminants. If wait time exceeds two hours, the surface should be brushed to remove 5. Cemented tires stored for extended possible contamination or oxidation periods should be covered, and may before applying cement or cushion. need to be cleaned and/or recemented. 2. The tread surface, which is to receive 6. Cement, if required, should be handled the new rubber, should be prepared according to the manufacturer’s to a symmetrical profile and proper recommendations. Follow all OSHA texture. The buffed surface should requirements and safety precautions. be free from contamination and Contact the individual materials have a TRMG BT3 or BT4 texture (see manufacturer for a copy of any RP 01/02-23 “BTS6 - Standard Buffing Material Safety Data Sheets (MSDS) Textures for Tire Retreading and Repair- needed. Also refer to federal, state, ing”). Buffed radial passenger car and local regulations, especially as tire casings must comply with the related to Volatile Organic Compound exposed cord limitations of FMVSS (VOC) emissions. 117 (see Reference Documents list following the Table of Contents). D. Building/Tread Application 3. Damage to the #2 or #3 belt greater than 3/8” (10.0 mm) may require a 1. If tire cord is exposed on any portion section repair. Consult the new tire of the buffed area, it should be manufacturer and/or the tire repair coated with a suitable vulcanizing materials manufacturer for further material before applying the tread information. rubber.

4 Light Truck Radial Fabric Body Ply Tires Retreading Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Radial Passenger Car and 2. Skives should be filled with a repair knife is used to make these cuts, the

material that is thoroughly stitched temperature of the knife must be RETREADING or extruded into place to eliminate all below 250°F to prevent scorching, trapped air, and reinforced if neces- and all cuts should be wiped with a sary (see Recommended Practices for solvent to prevent contamination. Tire Repairing). 4. Precure Tread Retreading 3. Mold Cure (Uncured Rubber) Retreading a. Tread rubber should be centered around the buffed circumference a. Apply cushion gum according to of the tire +/- 1/8” (3.0 mm) from the material supplier’s guidelines. the centerline. Tread rubber should be of crown, base, and gauge dimensions as b. Tread pattern should be matched required for matrix (i.e., mold) as closely as possible at the splice(s), design and size, and should provide if required, while assuring proper a minimum of 2/32” (1.5 mm) tread length. replacement undertread. c. Tread ends should be properly NOTE: prepared over the entire surface Tires with thicker tread depth may and be free of contaminants. If require additional material. required, the entire tread end surface should be cemented and b. Tread rubber bonding surfaces are gum stripped per posted procedure. not to be contaminated in any way. d. Tread stitching should be performed c. Tread rubber should be centered in such a way as to avoid trapping around the tire +/- 1/8” (3.0 mm) air, pulling the tread off center, and from the centerline. distorting, folding or wrinkling in the shoulders. d. Tread stitching should be performed in such a way as to avoid trapping air, pulling the tread off center, and E. Curing distorting, folding or wrinkling in the shoulders. 1. Mold Cure (Uncured Rubber) Retreading e. Splices, if any, should be made in such a manner as to ensure a. Tires should be kept free from minimum distortion of the rubber. contamination and stored in such a The shoulder area should be cut manner as to avoid distortion of the back at a slight angle to remove uncured rubber. excess rubber due to crowding in the smaller tire diameters. b. Follow manufacturers’ information and/or specifications on curing time, f. If splices are required, a 1/8” to temperature, pressure, and proper 1/4” (3.0 mm-6.0 mm) overlap, curing equipment (i.e., tubes and depending on tire size, should be rims, if used). used to allow for a small amount of crowding of the stock, which serves 2. Precure Tread Retreading to apply pressure in holding the two surfaces together. Retreaders a. Envelopes or diaphragms, if used, should use either a butt splice or a must be leak free. Various testing 45 degree beveled splice. If a hot methods are available, such as inflation or vacuum.

5 Light Truck Radial Fabric Body Ply Tires Retreading Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Radial Passenger Car and b. Wicking, if required, will be used to E. Approved procedures should be followed

allow for air removal from between when the tire is mounted and inflated. RETREADING the envelope or diaphragm on the The tire should be inspected at this enclosed tire surface during cure. time for any anomalies not previously detected. Follow the OSHA Standards c. Follow manufacturers’ information for Servicing Multi-piece and Single- and/or specifications on curing time, Piece Rim Wheels (29 C.F.R. § 1910.177, temperature, pressure, and proper as amended). curing equipment (i.e., tubes and rims, if used).

VI. FINAL INSPECTION A. After curing, the retreader should make a final examination of the tire, preferably while it is still warm, and while it is mounted on a spreader under adequate lighting (i.e., 200 fc / 2153 lx minimum, 300 fc / 3229 lx recommended) at the work surface, so that the interior and exterior of the tire is adequately exposed for visual and manual examination. B. The inside of the tire should be checked to ensure that all repairs are properly installed and bonded, and for any internal injuries or conditions that may have been missed during the initial inspection phase. C. The outside of the tire should be checked to ensure that it has been properly molded, cured, trimmed, and has all the required labeling, including as federally required in 49 C.F.R. Part 574 – Tire Identification and Record Keeping (as amended) and Retreaded Pneumatic Tires FMVSS 117 (see Reference Documents list following the Table of Contents). Retreads used in certain states may require additional labeling indicating that a tire has been retreaded in accordance with this retreading standard, and whether or not it qualifies for use in steer axle applications (see Appendices at the end of this document and Reference Documents list following the Table of Contents). D. Retreaded tires should not be returned to service for at least 24 hours since adhesion is reduced until the tire has cooled.

6 REPAIRING Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires The selection of of selection The . Tire Casing on Inspection Machine Tire REPAIRING GENERAL STATEMENT ABOUT TIRE

IV. installed. Inspection criteria should be posted in on on a tireinspection machine, orother machine capable of spreading thebeads under adequate contaminants (e.g., dirt, water, debris, sealants, sealants, debris, contaminants water, dirt, (e.g., other foreign materials prior to inspection. All determined to be sound and have been properly properly been have and be sound to determined technician and should include placing the tire casingtire the placinginclude should and technician lighting(i.e.,200 footcandles (fc) /2153 lux (lx) the at recommended) lx 300 / 3229 fc minimum, and visual for exposed adequately is casing the suppliers’ recommendations. repair units should be replaced unless they can be can they unless replaced be should units repair plants. retread manufacturers or material manufacturers regarding the retreading alteration or (i.e., repairing) of speed rated tires manual examination. the on based be should used materials repair work surface, so that the interior and exterior of of exterior and interior the that so surface, work visualmaterials, balancing materials,etc.) and/or All casings should be dry and free of all loose loose all of be dry free and should casings All Thorough Thorough inspectionshould bemade by a skilled Tire repair facilities should consult new tire 7 7 7 7 7 8 9 16 16 10 19 19 .. . Page ...... (NAIL HOLE REPAIR) HOLE (NAIL ......

Industry Recommended Practices for Tire Repairing for Tire Practices Recommended Industry REPAIR FINISHING REPAIR INSPECTION REPAIR FINAL INITIAL INSPECTION TIRE REPAIRS MINOR RUBBER PUNCTURE REPAIR REINFORCEMENT REPAIRS SECTION REPAIRS PURPOSE SCOPE TERMINOLOGY INDUSTRY TIRE ABOUT GENERAL STATEMENT REPAIRING

SCOPE INDUSTRY TERMINOLOGY INDUSTRY PURPOSE

X. XI. V. VI. VII. VIII. IX. Contents I. II. III. IV. III. II. I. to to be, and should not be, used as a substitutefor industry each that judgment the should member training, and supervisory practicesfor the proper the industry, for the permanent repairing of radial radial of repairing permanent the for industry, the make in establishing and implementing procedures,establishingandin make tires. damaged of repair passenger car and light truck radial fabric body ply fabric radial truck light and car passenger See Appendix 1 - Common Retread and Repair Repair and Retread 1 - Common See Appendix Recommended Recommended Practices (IRPs) to members of finishing, and final inspectionin final the practicesand finishing, used tire repairing industry. tire inspection, tire repair acceptable criteria, repairing tires for highway service. These IRPs are not intended Terminology - A Compendium of Industry Terms. Industry of - A Compendium Terminology This section addresses industry terminology, initial initial terminology, industry addresses section This The The purpose of this section is to offer Industry Repairing Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Radial Fabric Truck Car and Light Radial Passenger Repairing REPAIRING Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires inner liner or bead area on tires tires on area bead or liner inner identifiedtubeless as in depth information checking) beyond 2/32” (1.5 mm) mm) (1.5 2/32” beyond checking) cracking chemical/petroleum products, expose cord degradation, or loose inner liners inner loose or degradation, due to contamination from from contamination to due unless retreading is planned underinflated oroverloaded underinflated to be defective and unrepairable and be defective to sidewall, particularly in the upper upper the in particularly sidewall, sidewall tread depth (i.e., non-skid) remaining remaining non-skid) (i.e., depth tread breaks beyond repairable limits non-repairable bead area repairable injury (e.g., softness softness (e.g., injury repairable the in etc.) porosity, bulges, ripples, any evidence of having been run run been having of evidence any Crunching or popping sounds Open inner liner splices which which splices liner inner Open when flexed Flex breaks, X-breaks or impact X-breaks breaks, Flex the to damage Non-repairable Porous, contaminated from chemical contaminated Porous, or ply inside the on cords Loose cords body ply the to Injury Previously installed repairs found the in body plies the to Injuries Excessive oxidation (i.e., weather weather (i.e., oxidation Excessive Broken belts circumferentialRadial and/or sidewall missing or Improper Any signs of weakness or non- or weakness of signs Any Tires with less than 2/32” (1.5 mm) mm) (1.5 2/32” than less with Tires

g. g. i. c. e. e. Internal d. d. j. h. b. h. f. f. a.

2. 8 - CAUTION exposed bead wire bundle wire bead exposed to overlap the cord bodythe a repairable injury and penetrate penetrate and injury a repairable Surface cuts which exceedSurface cuts which of size the Damage which requires the repairs repairs the requires which Damage Broken, damaged, kinked or or kinked damaged, Broken, ARE NOT RECOMMENDED. NOT ARE

SPECIFIC REPAIR PROCEDURES. REPAIR SPECIFIC c. External b. a.

ASSEMBLY FOR INTERNAL INSPECTION. FOR INTERNAL ASSEMBLY CONTACT TIRE MANUFACTURERS FOR MANUFACTURERS TIRE CONTACT Inspection Criteria for TireRepairing 1. REPAIR MATERIAL MANUFACTURERS MATERIAL REPAIR

rubber stem Removal of damaged material Preparing the injured area Filling the injury with a suitable Reinforcing and sealing the repair area vulcanizing material or vulcanizing NEVER PERFORM A TIRE REPAIR WITHOUT REPAIR A TIRE PERFORM NEVER

REMOVING THE TIRE FROM THE RIM/WHEEL THE RIM/WHEEL FROM THE TIRE REMOVING or injuries or which require repairs beyond beyond repairs require which or injuries or they have any of the following conditions conditions following the of any have they (see IIA and II I, Tables in shown limits the INITIAL TIRE INSPECTION TIRE INITIAL No tires should be accepted for repairing if if repairing for be accepted should tires No A. DO NOT MIX PRODUCTS DIFFERENT FROM Tables section at the end of this document). this of end the sectionat Tables • • • • OUTSIDE-IN OR ON-THE-WHEEL TIRE REPAIRS REPAIRS TIRE OUTSIDE-IN OR ON-THE-WHEEL disposal. mendations for installation manufacturers’ Material Safety Data Sheets and instructions. Follow repair materials manufacturers’ recom materials repair Follow Refer Refer to the information on the product or (MSDS) and follow guidelines for handling and handling for guidelines follow and (MSDS)

Repairing Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Ply Body Fabric Radial Truck Light Car and Passenger Radial Repairing Repair procedures require the following: V. REPAIRING Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires - flame near fire, solvents CAUTION WARNING Probing and Foreign Material Removal Material Foreign and Probing Inspection

of damage. If there is ply body damage, body damage, ply is there If damage. of document (see sectionIX). (see document Steps for Minor Rubber Repair Rubber Minor for Steps ultrasonics, electrostatic, high pressure refer to the Section Repairs portion of this this of portion Repairs Section the to refer nondestructive inspection equipment inspection. casing for utilized be etc.) tester, any foreign material. type some of that recommended also Inspect the injury to determine the extent extent the determine to injury the Inspect is it inspection, visual to addition In (e.g., holography, shearography, X-ray, X-ray, shearography, holography, (e.g., Use a probe to inspect the damage. Remove Remove damage. the inspect to a probe Use 2. 1. REPAIR MATERIAL MANUFACTURERS MATERIAL REPAIR

D. repair specifications. repair and maintain its air retention capability. and maintain its air retention capability. a minor rubber repair. rubber a minor Consult casingmanufacturer for bead area DO NOT MIX PRODUCTS DIFFERENT FROM The steps listed below are essential to perform to essential are below listed steps The DO NOT use flammable disposal. mendations for installation manufacturers’ Material Safety Data Sheets and instructions. serious personalserious injury or death. or any other source of ignition. Explosiveforce and/or fireand/or from ignition of solventscould cause Follow repair materials manufacturers’ recom materials repair Follow Refer to the information on the product or (MSDS) and follow guidelines for handling and handling for guidelines follow and (MSDS) 9 prior to prior to Bead Area Repair Inner Liner Repair Spot Repair

B. it is also recommended that some type of type some of that recommended also is it is found in the valve assembly or in the bead bead the in or assembly valve the in found is casing manufacturerfor inner liner repair cannot be spot repaired but should be be should but repaired be spot cannot sectionrepairing. for considered conditions, checkthe valve assembly and electrostatic,high etc.) pressure tester, be detection solution, where practical,detectionwhere solution, demounting and deflating the tire. If a leak a If tire. the deflating and demounting utilized for casing inspection. for casing utilized specifications. the original contour of the bead. In addition, addition, In bead. the of contour original the since the tire will not hold air. hold not will tire the since not expose cord, tool damage or blisters, blisters, or damage tool cord, expose not may be repaired in tubeless tires. Consult bead repairs on a tubeless tire should restore restore should tire tubeless a on repairs bead repairs. In no case should a kinked or broken broken or a kinked should case no In repairs. of evidence with Tires repaired. be bead bead area separationor rusting inthe body plies should be rejected. bead area for leaks using a water or leak leak or a water using leaks for area bead nondestructive inspection equipment (e.g., ultrasonics, X-ray, shearography, holography, area, certain repairs may not be possible bepossible not may certain repairs area, C. MINOR RUBBER REPAIRS RUBBER MINOR Open Open inner liner splices, cracks which do Bead Bead area repairs on all tiresshould restore Bead area repairs are limited to rubber only only rubber to limited are repairs area Bead Radial Radial tireswith damage to the body cords In In additionto checkingfor non-repairable Furthermore, along with visual inspection, A.

Repairing Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Ply Body Fabric Radial Truck Light Car and Passenger Radial Repairing but should be performed in a full-service repair a full-service repair in be performed should but facility. See Appendix 1 - Common Retread and and Retread - Common 1 See Appendix facility. Minor repairs are generally rubber only repairs, repairs, only rubber generally are repairs Minor Facility”. Repair Terminology – A Compendium of Industry Industry of – A Compendium Terminology Repair VI. Terms for a definition of “Full Service Repair Service Repair “Full of a definition for Terms REPAIRING Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires (NAIL HOLE REPAIR) HOLE (NAIL ARE NOT RECOMMENDED. RECOMMENDED. NOT ARE SPECIFIC REPAIR PROCEDURES. REPAIR SPECIFIC Cementing Curing

Filling

ASSEMBLY FOR INTERNAL INSPECTION. FOR INTERNAL ASSEMBLY 8. 6. climate conditions, extend the dryingconditions, extendtimethe climate equipment and materials manufacturers’ streaking. Allow the cement to dry for the drythe to for cement the Allow streaking. temperature, and pressure according to the material. prepared surface prepared or nowith puddling humid and/or cold In time. recommended recommendations. For chemically activated repairs, allow sufficienttime for curing as manufacturer. the by recommended as recommended by the manufacturer. the by recommended as Cure the repair for the specified time, time, specified the for repair the Cure Fill the injurywith a suitable vulcanizing Apply the appropriate cement to the the to Apply cement appropriate the 7. CONTACT TIRE MANUFACTURERS FOR MANUFACTURERS TIRE CONTACT rubber stem Removal of damaged material Preparing the injured area Filling the injury with a suitable Reinforcing and sealing the repair area vulcanizing material or vulcanizing NEVER PERFORM A TIRE REPAIR WITHOUT REPAIR A TIRE PERFORM NEVER

REMOVING THE TIRE FROM THE RIM/WHEEL THE RIM/WHEEL FROM THE TIRE REMOVING PUNCTURE REPAIR REPAIR PUNCTURE • • • • OUTSIDE-IN OR ON-THE-WHEEL TIRE REPAIRS REPAIRS TIRE OUTSIDE-IN ON-THE-WHEEL OR

or leak detection solution,where practical. If a the valve and outer surface for leaks using a water water a using leaks for surface outer and valve the leak is found in the valve assembly or in the bead bead the in or assembly valve the in found is leak the in found is leak no If air. hold not will tire the tire. the demount and deflate, totally injury, the area, a puncture repair may not be possible since since be possible not may repair a puncture area, Prior to demounting and deflating the tire,check theand deflating to Prior demounting Repair procedures require the following: valve assembly or bead area, proceed by marking marking by proceed area, bead or assembly valve VII. 10 near fire, flame cement WARNING Buffing Pre-Cleaning Cleaning

injury. 5. bonding bonding surfaces because the unfiltered repairs (see RP 01/02-23 “BTS6 - Standard “BTS6 - Standard 01/02-23 RP (see repairs thematerial. repair Texturize area with bufferand buffing appropriate tool, while possible. as small as area repair the keeping from the buffed area with a fine wire brush brush wire fine a with area buffed the from 3. and vacuum to provide a clean, dry surface. dry surface. a clean, provide to vacuum and air lines may contain contaminants such as oil and moisture, which can reduce adhesion. a low-speed (i.e., 5,000 rpm maximum) 5,000 maximum) rpm (i.e., a low-speed Do not use compressed air to clean clean to air compressed use Do not Remove any rubber dust and contaminants Buff the injury to achieve a uniform a uniform achieve to Buff injury the BuffingTextures for Tire Retreading and loose or damaged all Remove Repairing”). Remove all contaminants from around the 4. TRMG BT1 or BT2 buff texture for all BT2 all or buff for BT1 texture TRMG overloaded, and should be inspected accordingly. ensure that the repair area is free of contaminants. of free is area repair the that ensure sealing capabilities require specialized repair should be contactedfor recommendations. It may techniques. The tire and/or sealant manufacturers sealant and/or tire The techniques. to pre-cleaning, 3, step repeat be necessary to puncture sealant(s) may have been have may puncture damaged sealant(s) as a result of being run underinflated and/or

2.) Tires2.) that are manufactured with puncture 1.) 1.) Tires that contain any type of aftermarket DO NOT use flammable serious personalserious injury or death. or or any other source of ignition. Explosive force and/or and/or fire from ignition ofcement could cause Repairing Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Ply Body Fabric Radial Truck Light Car and Passenger Radial Repairing NOTE: REPAIRING Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires rating (GVWR) of 10,000 lbs. or less. Remove Penetrating Object Penetrating Remove FIGURE 1 FIGURE Probe the Injury - Inside Tire Probe make repairs where the injury damage damage injury the where repairs make Steps forSteps Puncture Repair

images below and on the following pages. following the on and below images B. puncture in radial passenger car and light truck light and car passenger radial in puncture radial fabric body ply tires. Seetire repair The steps listed below are essential to repair a repair to essential are below listed steps The Tire sizes for lightTireforvehiclessizes include radialallpassenger cartires the Federal Motor Vehicle Safety Standards as motor vehicles with a gross vehicle weight 1 Range E). Light vehicles are defined by49 C F R §571.139 of and some light truck radial fabric body ply tires (up to Load extends into the shoulder/belt extends edge into area the OR shoulder/belt where DO NOT DO NOT the injury extends at an angle into the shoulder area. shoulder the into angle an at extends injury the 11 Mark the Injury - Outside Tire Probe the Injury - Outside Tire Probe tire puncture repairs, 1 Radial Passenger Car and Light Truck Truck Light Car and Passenger Radial Tire Puncture Body Ply Fabric Radial Repair

PUNCTURE REPAIR PUNCTURE REPAIR truck truck radial fabric body ply tireand indicates tread the to limited are repairs puncture that should be limited to the tread area only and and only area tread the to be limited should not not exceed 1/4” (6.0 mm) in diameter after preparation. radial fabric body ply area only, as generally depicted in the graphic. the in depicted generally as only, area Figure 1represents a radialpassenger car/light Radial passenger car and some light truck truck light some and car passenger Radial A. Mark the Injury - Inside Tire Mark and Probe the Injury Mark and Probe Repairing Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Ply Body Fabric Radial Truck Light Car and Passenger Radial Repairing Place Tire on Inspection Machine Place Tire of of tireservice (e.g.,service description, run-flat technology, commercial service applications, etc.). applications, service commercial technology, should should be based on or recommendations repair policies policies of the tire manufacturer and/or type Not all tires can be repaired. Specific repair limits repair Specific repaired. be can tires all Not NOTE: rated tires. rated and repair material manufacturer regarding the alteration(i.e.,retreading or repairing) of speed Determine the extent and location of any injuries. Repair shops should consult the tire manufacturer REPAIRING Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Drill the Injury - Outside Tire Inspection Preparation of the Injury of the Preparation

inside a minimum of three times with the the with times of three a minimum inside or other suitable tool, following the angle angle the following tool, suitable other or of penetration. Toolsused must remove hole. the elongate to not careful ensure complete damage removal, being penetrationis (6.01/4” mm) or less. In longer no is this present, If splits. liner the damaged steel and create a round a round create and steel damaged the to tire the of outside the from times three 3. hole. Repeat this process a minimum of of a minimum process this Repeat hole. radial plies surrounding the Remove injury. addition, inspect prepared injury for inner appropriate carbide cutter on a low speed speed low a on cutter carbide appropriate any additional damage found. damage additional any Inspect the making injury, surethe 4. (i.e., 1,200 rpm maximum) air/electric drill, 1,200 air/electric rpm(i.e., maximum) Use a probe to check for any splits in the the in splits any for check to a probe Use When possible, drill the injury from the the from injury the drill possible, When overloaded, and should be inspected accordingly. overloaded, and should be inspected accordingly. ensure that the repair area is free of contaminants. of free is area repair the that ensure sealing capabilities require specialized repair should be contactedfor recommendations. It may techniques. The tire and/or sealant manufacturers sealant and/or tire The techniques. to pre-cleaning, 2, step repeat be necessaryto puncture sealant(s) may have been have may puncture damaged sealant(s) as a result of being run underinflated and/or 2.) Tires2.) that are manufactured with puncture 1.) 1.) Tires that contain any type of aftermarket NOTE: - 12 - Drill the Injury - Inside Tire flame near fire, solvents cont. CAUTION WARNING Pre-Cleaning Probing and Foreign Material Removal Material Foreign and Probing use flammable

injury. that has penetrated the tire. the penetrated has that mine mine the angle and size of penetration. Remove all contaminants from around the Probe the injury with a tire probe to deter to probe tire a with injury the Probe Inspect andremove anyforeign material 2. 1. REPAIR MATERIAL MANUFACTURERS MATERIAL REPAIR Pre-Clean and Drill Pre-Clean DO NOT MIX PRODUCTS DIFFERENT FROM Scrape Away Contaminants Away Scrape PUNCTURE REPAIR PUNCTURE REPAIR disposal. mendations for installation manufacturers’ Material Safety Data Sheets and instructions. Follow repair materials manufacturers’ recom materials repair Follow Refer Refer to the information on the product or (MSDS) and follow guidelines for handling and handling for guidelines follow and (MSDS) DO NOT DO serious personalserious injury or death. or any other source of ignition. Explosiveforce and/or fireand/or from ignition of solventscould cause Repairing Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Ply Body Fabric Radial Truck Light Car and Passenger Radial Repairing

REPAIRING Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Vacuum the Repair Area Repair the Vacuum Vacuum the Repair Area Repair the Vacuum Two Piece Repair Unit Piece Repair Two ensure that crayon marks are not removed removed not are marks crayon that ensure degrees, depending on repair manufacturer, use a two-piece repair unit system. unit a two-pieceuse repair the injury and outline an area about 1/2” 1/2” about area an outline and injury the recommendations. Centerthe unit over when buffing. For injuries with an angle greater than 25 than greater angle an with injuries For (13.0 mm) larger than the repair unit, to to unit, repair the than larger mm) (13.0 13 Brush the Repair Area Brush the Repair Brush the Repair Area Brush the Repair cont. cont. One Piece Repair Unit One Piece Repair Repair Unit Selection Unit Repair PUNCTURE REPAIR PUNCTURE REPAIR Repair Unit Selection Unit Repair

5. sectionIX.B.). based on repair material manufacturer a puncture repair. Refer to the Section Section the to Refer repair. puncture a Selectthe appropriate repair unit Repairs Repairs portion of this document (see Buff the Repair Area Buff the Buff the Repair Area Buff the PUNCTURE REPAIR PUNCTURE REPAIR Repairing Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Ply Body Fabric Radial Truck Light Car and Passenger Radial Repairing Buff and Clean Repair Area for a One-Piece Repair Unit for a One-Piece Repair Area Buff and Clean Buff and Clean Repair Area for a Two-Piece Repair Unit Two-Piece for a Repair Area Buff and Clean REPAIRING Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires cement near fire, flame Buff the Cut Stem Stitch the Repair Unit the Stitch Install the Repair Unit Repair the Install WARNING Cementing

8. surfaces because the unfilteredair lines may contain contaminants such as oil and and oil as such contaminants contain may whichmoisture, can reduce adhesion. surface and, if required, to the back of the the of back the to required, if surface and, Apply appropriate cement to the buffed DO NOT use flammable serious personalserious injury ordeath. or or any other source of ignition. Explosive force and/or and/or fire from ignition ofcement could cause 14 Cement the Buffed Area the Buffed Cement Cut the Stem - Outside Tire Cut the Stem Press Repair Unit into Place Unit into Repair Press cont. Inner Liner Buffing

Cleaning

6. the the outline, buffwithin the marked area speed a low using evenly and thoroughly from the buffed area with a fine wire brush brush wire fine a with area buffed the from not not to expose or damage the tire casing cords. Bufftosurface; body avelvet (ply) and vacuum to provide a clean, dry surface. Do not use compressed air to clean bonding bonding clean to air compressed use Do not Remove any rubber dust and contaminants (i.e., 5,000(i.e., rpm buffermaximum) with a finewire brush or Take care gritted rasp. 7. To To prevent contamination and preserve TRMG BT1 or BT2 or texture. BT1 TRMG Apply Repair Sealant Apply Repair Cement the Injury Channel Cement PUNCTURE REPAIR PUNCTURE REPAIR Repairing Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Ply Body Fabric Radial Truck Light Car and Passenger Radial Repairing Pull Repair Unit Stem Through Tire Through Unit Stem Pull Repair Cement and Install One-Piece Repair Unit One-Piece Repair and Install Cement REPAIRING Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Buff the Cut Stem Stitch the Repair Unit the Stitch Cut the Stem - Inside Tire Cut the Stem cement the injury channel, insert the stem from the inside of the tire, of the stem from the tire, the inside the against snug is unit repair the the innerliner. prepared and cemented surface cemented and ofprepared and and pull through untilthe base of When using a one-piece unit, repair

Repair Unit Repair Installation a.

it is installed. beads beads of the tire are in arelaxed position. Avoid trapping unit. repair the on markings air and/or possible bridging of the unit as as unit the of bridging possible and/or air Repair units are to be installed while the the while installed be to are units Repair Align the repair unit according to the the to according unit repair the Align 10. 15 Insert the Stem Install the Repair Unit the Repair Install Cut the Stem - Outside Tire Cut the Stem cont. use forced air or an outside heat or outside an use air heat forced Fill the Injury the Fill

9. the injury with the appropriate material. the recommended time. While drying, the material or material a rubber vulcanizing stem, fill repair unit. Allow the cement to dry to for cement the Allow unit. repair tire. the of bottom the at positioned not If using uncured/suitable vulcanizing tire should be rotated so that the injury is injury the that so rotated be should tire Apply Repair Sealant Apply Repair Cement the Buffed Area the Buffed Cement Cement the Injury Channel Cement PUNCTURE REPAIR DO NOT DO NOT source to accelerate drying time. Refer to repair materials manufacturer recommendations. Repairing Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Ply Body Fabric Radial Truck Light Car and Passenger Radial Repairing Cement and Install Two-Piece Repair Unit Repair Two-Piece and Install Cement REPAIRING Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires - flame near fire, solvents CAUTION WARNING use flammable SectionRepair Limits Steps for Repairs Steps Reinforcement REINFORCEMENT REPAIRS

REPAIR MATERIAL MANUFACTURERS MATERIAL REPAIR

document document (see sectionIX.B., Steps for Section SECTION REPAIRS SECTION and equipment being used. Refer Refer to the Section Repairs portion this of Repairs.) A. A. tires. The method is dependent on the materials materials the on dependent is method The tires. DO NOT MIX PRODUCTS DIFFERENT FROM There There are several methods of section repairing

DO NOT DO serious personalserious injury or death. or any other source of ignition. Explosiveforce and/or fireand/or from ignition of solventscould cause disposal. mendations for installation manufacturers’ Material Safety Data Sheets and instructions. Follow repair materials manufacturers’ recom materials repair Follow Refer to the information on the product or (MSDS) and follow guidelines for handling and handling for guidelines follow and (MSDS) IX. repair limits. These limits should be based on on based be should limits These limits. repair recommendations ofthe tiremanufacturer, repair service. type tire and of manufacturer, materials repair limits. These limits should be based on on based be should limits These limits. repair recommendations ofthe tiremanufacturer, repair service. type tire and of manufacturer, materials and repair material manufacturerspecificregardingmaterial repair and and repair material manufacturerspecificregardingmaterial repair and Determine Determine the extent and locationof any injuries. Repair shops should consult the tiremanufacturer Determine Determine the extent and locationof any injuries. Repair shops should consult the tiremanufacturer VIII. 16 DO stem), cement theinjury stem), channel stemdesigned for injury. that size trim the excess material inside the the inner liner to accommodate the and and fill the injury from the inside appropriate repair size unit. with a suitable vulcanizing rubber (i.e., (i.e., separate repair unit and filler Without stretchingthe stem, cut/ tire, and buff the stem flush with When usinga two-piece unit repair

Stitching Inspect Areas Repair Curing b.

or a plug (stem) only is not a proper puncture puncture proper a not is only (stem) a plug or chamber, follow the manufacturers’chamber, calculating cure time. Cure the repair for the sufficient allow repairs, activated chemically using using a spotter, section mold curing or unit, look for signs of tire casing body cords. cords. body casing tire of signs for look unit, stem, must be cured completely. When When completely. be cured must stem, andspecified time,temperature, pressure starting from the center, and work outwards tread. the with level is it until repair. repair. (See section X,Repair Finishing.) manufacturer. recommendations. Also follow the manufacturers’ recommendations for manufacturers’ recommendations. For to the edges. Check for proper installation. installation. for proper Check edges. to the or stretch to not sure surface making tread pull the stem while cutting. If the stem is stem the If cutting. while stem the pull lightly buff cutting, after tread with flush not and the edge of the repair unit. A patch only only patch A unit. repair the of edge the and according to the equipment and materials Cut the fill material flush with the outer For all methods, stitch the entire repair unit repair entire the stitch methods, all For If the buffed area extends beyond the repair repair the beyond extends area buffed the If vulcanizing material or vulcanizing rubber time for curing as recommended by the Apply repair sealant to the over-buffed area area over-buffed the to sealant repair Apply 13. 12. 11. The repair unit and uncured/suitable The unit and uncured/suitable repair cement the stem. cement Instead, the injury Repairing Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Ply Body Fabric Radial Truck Light Car and Passenger Radial Repairing channel. NOT Remember, for both types of repair units, units, types repair of both for Remember, REPAIRING Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Skiving Repair Unit Selection Unit Repair Inner Liner Buffing

6. expose only tread belt cables believed believed cables belt tread only expose cuts or no that ensure to removal damage on the construction of the cables. or body cords the to tire damage the of and the size 5. separations remain in the tire. the in remain separations to achieve a uniform TRMG BT2 or BT3 BT3 BT2 or TRMG uniform a achieve to after area repair the probe Always texture. to to be damaged (i.e., just until they are trimmed back to solid rubber. Buff with tool texture buffing appropriate and buffer texture tool, remove all damaged rubber rubber damaged all remove tool, texture Use possible. as small as area injured the speed speed (i.e., 5,000 rpm maximum) buffer maximum) buffer and appropriate buffing buffing appropriate and buffer maximum) the entire injury has been removed. Refer Refer removed. been has injury entire the (see diagrams related and II I and Tables to materials manufacturers’ charts for proper selection. unit repair slightly be should area buffed The texture. larger than the repair unit. a low-speed (i.e., 5,000 rpm maximum) 5,000 maximum) rpm (i.e., a low-speed for Maximum Injury Limits, and to repair above the steel cables, taking care to keep keep to care taking cables, steel the above a low-speed on tool texture appropriate an remainingaway rubber and very lightly and and appropriate buffing texture tool to buffed BT2 or BT1 TRMG uniform a achieve Select the appropriate repair unit based based unit repair appropriate Select the Buff the area for the repair unit with a low low a with unit repair the for area the Buff visible). All damaged loose fabric must be must fabric loose damaged All visible). Final measurements should be made when when made be should measurements Final (i.e., 5,000(i.e., rpm buffermaximum) to buff 4. Using a low-speed (i.e., 5,000 rpm 5,000 rpm (i.e., a low-speed Using Tablessection at the end of this document) overloaded, and should be inspected accordingly. ensure that the repair area is free of contaminants. of free is area repair the that ensure sealing capabilities require specialized repair should be contactedfor recommendations. It may techniques. The tire and/or sealant manufacturers sealant and/or tire The techniques. to pre-cleaning, 3, step repeat be necessary to as a result of being run underinflated and/or 2.) Tires2.) that are manufactured with puncture 17 - flame near fire, solvents CAUTION WARNING Pre-Cleaning Inspection Probing and Foreign Material Removal Material Foreign and Probing use flammable

injury. determine repairability and the extent of of extent the and repairability determine damage. Steps forSteps SectionRepairs 3. foreign material that has penetrated the tire. Remove all contaminants from around the Inspect, mark, and measure all injuries to to injuries all measure and mark, Inspect, Use a probe to inspect and remove any any remove and inspect to a probe Use 2. 1. REPAIR MATERIAL MANUFACTURERS MATERIAL REPAIR

B. a section repair in a tire. in a a sectionrepair and and repair unit selection should be made Final measurements to determine repairability removed. been has injury the of all when DO NOT MIX PRODUCTS DIFFERENT FROM The The steps listed below are to essential make DO NOT DO disposal. mendations for installation manufacturers’ Material Safety Data Sheets and instructions. serious personalserious injury or death. or any other source of ignition. Explosiveforce and/or fireand/or from ignition of solventscould cause Follow repair materials manufacturers’ recom materials repair Follow Refer Refer to the information on the product or (MSDS) and follow guidelines for handling and handling for guidelines follow and (MSDS) puncture sealant(s) may have been have may puncture damaged sealant(s) 1.) 1.) Tires that contain any type of aftermarket Repairing Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Ply Body Fabric Radial Truck Light Car and Passenger Radial Repairing NOTE: REPAIRING Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires - installation. Inspect repair area. casing bodycasing cords. over-buffedarea and the edge of unit is snug against the prepared prepared the against snug is unit the repair unit, look for signs of tire tire of signs for look unit, repair the sectioninsertunit, repair the stem to the edges. Check for proper proper for Check edges. the to through until the base of the repair repair the of base the until through liner. the repair unit. from the center, and move outwards outwards move and center, the from from from the inside of the tireand pull facturer, apply repair sealant to the the to sealant repair apply facturer, and cemented surface of the inner inner the surface of cemented and Stitch the entire repair unit starting unit repair entire the Stitch If If the buffedarea extends beyond If recommended manu by repair When using a one-piece chemical

c. Fill the Injury the Fill Unit Repair Installation Curing b. a.

9. chamber, follow the manufacturers’chamber, on the repair unit. repair the on DO NOT continueDO NOT the repair if the buffed using using a spotter, section mold curing or recommended as curing for time sufficient stem must be cured completely. When When completely. cured be must stem chemically For pressure. and temperature, by the manufacturer. stem. recommendations. Alsofollow the repair material and equipment manufacturers’ recommendations for calculating cure beads beads of the tirein the relaxed position. activated repair unit application, allow area exposes radial ply cords. ply radial exposes area Fill the injury with an uncured/suitable the with installed be to are units Repair vulcanizing material or vulcanizing rubber vulcanizing materialor vulcanizing rubber time. Cure the repair for the specified time, time, specified the for repair the Cure time. Align the repair unit according to markings markings to according unit repair the Align 11. 10. The repair unit and uncured/suitable The unit and uncured/suitable repair 18 cement near fire, flame WARNING Cementing

Cleaning

use forced air or an outside heat source to to source heat outside an or air forced use 8. inside the tire, and buff the stem flush flush buff stem and the tire, the inside cement to the back of the repair unit if if unit repair the of back the to cement dryingconditions, extendtimethe climate evenly to all surfaces with no puddling or or puddling no with surfaces all to evenly surfaces because the unfilteredair lines may contain contaminants such as oil and and oil as such contaminants contain may whichmoisture, can reduce adhesion. surface depending on the repair method method repair the on depending surface drythe to for cement the Allow streaking. stretching the stem, trim the excess material being used. Also apply the appropriate appropriate the apply Also used. being be The should applied cement required. humid and/or cold In time. recommended materialor vulcanizing rubber stem. Without from the buffed area with a fine wire brush brush wire fine a with area buffed the from from the inside with a suitable vulcanizing and vacuum to provide a clean, dry surface. as recommended by the manufacturer. the by recommended as appropriate repair size unit. Cement the injury channel and thethe fillCement injury injury channel Do not use compressed air to clean bonding bonding clean to air compressed use Do not Remove any rubber dust and contaminants with the inner liner to accommodate the Apply the appropriate cement to the buffed the to cement appropriate the Apply 7. use flammable flammable DO NOT use serious personalserious injury or death. or any other source of ignition. Explosive force force Explosive ignition. of source other any or and/or fire from ignition of cement could cause cause could cement of ignition from fire and/or installed before buffing. buffing. before installed rubber rubber stem is used to fillan it injury, must be If a suitable vulcanizing material or vulcanizing vulcanizing or material vulcanizing a suitable If Repairing Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Ply Body Fabric Radial Truck Light Car and Passenger Radial Repairing DO NOT DO NOTE: manufacturer recommendations. accelerate drying accelerate time. Referto materials repair REPAIRING Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Inside InspectionInside Outside Inspection

detected. Follow the OSHA Standards for returned to service for a minimum of 24 24 of a minimum servicefor to returned hours afterthe curing cycle,when they reachedhave ambient air temperature. Servicing Multi-piece and Single-Piece Section repaired tires should not be Rim Wheels (29 C.F.R. § 1910.177). C.F.R. (29 Wheels Rim when when the tire is mounted and inflated.

time for any anomalies not previously Approved procedures should be followed be should followed procedures Approved The The tire should be inspected this at

or or conditionsthat may have been missed cured, trimmed, and has all the required ensure thatall repairsare properly installed during the initial inspection phase. inspection initial the during to ensure that it has been properly molded, molded, properly been has it that ensure to labeling. and bonded,and for any internal injuries Criteria for Inspection Repair 2. 1. The The outside of the tire beshould checked The inside of the tire should be checked to be Theshould of checked tirethe inside

3. 4. inspection of repaired a tire. During the inspection process, the same stepsused in B. the Final Repair Inspection. Repair Final the Initial TireInspection should be followed in The steps listed below are essential for proper proper for essential are below listed steps The 19 Buffing Inspect Areas Repair Tread Design Tread

contour contour and appearance of the tire. The Steps for Repair Finishing forSteps Repair the precured stem repair to the original may material repair rubber the surfaceof surrounding surface. (See section XI.B., not extend over 2/32” (1.5 mm) above the the above mm) (1.5 2/32” over extend not General Inspection Repair General Repair Finishing General Repair Criteria for Repair Inspection.) Repair for Criteria Restore tread design in the crown area. crown the in design tread Restore Buff the cured rubber filler material or trim trim or material filler rubber cured the Buff 2. 1.

unit, look for signs of tire casing body cords. body casing tire of signs for look unit, If the buffed area extends beyond the repair repair the beyond extends area buffed the If 12. B. completion of a tire repair. tire of a completion used to cure the repair, conduct the inspection used to the cure repair, unit. (See section XI.B., Criteria for Repair Repair for Criteria XI.B., section (See unit. should be placed on or next to the repair repair next or on the to be placed should recommended) at the work surface. If heat is heat If surface. work the at recommended) mounted on a spreader under adequate lighting performance and appearance of the repaired FINAL REPAIR INSPECTION REPAIR FINAL REPAIR FINISHING REPAIR Conduct a final examination of the tire whileis it while the repair is still warm. still is repair the while Inspection.) Finishing is necessary to ensure satisfactory dating and codes) internal other or Code Plant (i.e., 200 fc / 2153 lx minimum, 300 fc / 3229 lx 300 / 3229 fc minimum, lx / 2153 200 fc (i.e., A. A. tire. Repair identification (typicallythe DOT-R The steps listed below are essential for proper proper for essential are below listed steps The

Repairing Radial Passenger Car and Light Truck Radial Fabric Body Ply Tires Ply Body Fabric Radial Truck Light Car and Passenger Radial Repairing XI. X. RETREADING Light Truck Radial Steel Body Ply Tires Load Range E and Above Tire Casing on Inspection Machine Tire General Statement

SELECTION FOR RETREADING FOR SELECTION inspection. All repair units should be replaced replaced be should units repair All inspection. or other machine capable of spreading the the spreading of capable machine other or criteria should be posted in retread plants. retread in posted be should criteria etc.) and/or other foreign and/or etc.) materials prior to skilled operator and should include placing unless they can be determined to be sound be sound to be determined can they unless the the tire casingon atire inspection machine, of exterior and interior the so that surface, sealants, visual materials, balancing materials, beads under adequate 200 lighting (i.e., the casing is adequately exposed for visual loose contaminants (e.g., dirt, water, debris, debris, water, dirt, (e.g., contaminants loose manufacturers or material manufacturers footcandles (fc) / 2153 lux (lx) minimum, minimum, (lx) lux / 2153 (fc) footcandles and manual examination. and have been properlyandhave installed. Inspection INITIAL CASING INSPECTION AND CASING AND INSPECTION INITIAL Retreaders should consult new tire 300 fc / 3229 lx recommended) at the work work the at recommended) lx 300/ 3229 fc A. All casings should be dry and free of all all of dry be free and should casings All Thorough Thorough inspectionshould bemade by a

IV. 20 24 20 20 20 20 22 age P ......

Industry Recommended Practices for Tire Retreading for Tire Practices Recommended Industry SCOPE INDUSTRY TERMINOLOGY INDUSTRY PURPOSE INITIAL CASING INSPECTION AND SELECTION RETREADING FOR PROCESSING INSPECTION FINAL PURPOSE SCOPE TERMINOLOGY INDUSTRY

IV. V. VI. Contents I. II. III. III. II. I. in the tire retreading industry. retreading tire the in casing casing inspection and selection for retreading, industry member should in establishing make of E or above, for highway service. These IRPs IRPs These service. highway for above, E or of the industry, for the manufacturing of retreaded retreaded of manufacturing the for industry, the processing, processing, and finalinspection guidelines used supervisory practicesfor the proper inspection, tires. worn of retreading and selection, light light truck radial steel body ply tires,or those are not intended to be, and should not be, used used be, not should and be, to intended not are each that judgment the for a substitute as and implementing procedures, training, and See Appendix 1 - Common Retread and Repair Repair and Retread 1 - Common See Appendix with similar material body and a load ply, range Recommended Recommended Practices (IRPs) to members of Terminology - A Compendium of Industry Terms. Industry of - A Compendium Terminology This section addresses industry terminology, initial initial terminology, industry addresses section This The purpose of this sectionis to offer Industry Retreading Light Truck Radial Steel Body Ply Tires Load Range E and Above E and Load Range Body Ply Tires Radial Steel Truck Light Retreading Retreading Light Truck Radial Steel Body Ply Tires Load Range E and Above Light Truck Radial Steel Body Ply Tires Load Range E and Above regarding the alteration (i.e., retreading or i. Radial cracking

repairing) of speed rated tires. RETREADING j. Improper labeling In addition to visual inspection, it is also recommended that some type of 2. Internal nondestructive inspection equipment (e.g., holography, shearography, X-ray, ultrasonics, a. Injuries to the body plies in the electrostatic, high pressure tester, etc.) be non-repairable bead area utilized for casing inspection. b. Loose cords on the inside ply or evidence of having been run B. Inspection Criteria for Light Truck underinflated or overloaded Radial Steel Body Ply Tire Casings Used on the Highway c. Non-repairable damage to the inner liner or bead area on tires No tire casings should be accepted for identified as tubeless retreading having any of the following conditions or injuries which require repairs d. Open inner liner splices which beyond the limits of the IRPs or beyond the expose cord limits outlined in Table I (see Tables section at the end of this document). e. Flex breaks, X-breaks or impact breaks 1. External f. Porous, contaminated from chemical a. Ply separation beyond repairable degradation, or loose inner liners limits g. Previously installed repairs found b. Tread separations which cannot be to be defective and unrepairable removed during buffing h. Suspected of potential zipper c. Broken, damaged, kinked or damage exposed bead wire bundle • Cuts, snags or chips exposing d. Excessive oxidation (i.e., weather body cords checking) extending to the body plies or deeper than 2/32’’ (1.5 mm) • Distortions or undulations (i.e., ripples and/or bulges) visible e. Circumferential cracking when using an indirect light source which will produce f. Any signs of weakness or non- shadows left by any sidewall repairable injury (e.g., softness irregularities due to contamination from chemical/petroleum products, • Creasing, wrinkling, cracking or ripples, bulges, porosity, etc.) in the discoloration of the inner liner sidewall, particularly in the upper sidewall • Soft spot(s) in the sidewall flex area g. Crunching or popping sounds when flexed • Protruding filaments indicating broken cords h. Surface cuts which exceed the size of a repairable injury and • Any popping sound when penetrate the cord body feeling for soft spots or when rolling the tire

21 Retreading Light Truck Radial Steel Body Ply Tires Load Range E and Above Light Truck Radial Steel Body Ply Tires Load Range E and Above contamination or oxidation. If wait

INJURY LIMITS time exceeds two hours, the surface RETREADING should be brushed to remove possible • Maximum of 3 repairs* contamination or oxidation before • All shoulder repairs get #22 or larger applying cement or cushion. repair units • Look closely for run flat conditions; “zipper 2. The tread surface, which is to receive potential high” the new rubber, should be prepared to a • 6 years or newer casing (drive tires) symmetrical profile and proper texture. • 4 years or newer casing (steer tires) The buffed surface should be free from • Check California Reg. (RFS-1) contamination and have a TRMG BT3 • Refer to tire and repair material or BT4 texture (see RP 01/02-23 “BTS6 manufacturers when in doubt - Standard Buffing Textures for Tire Retreading and Repairing”). *Refer to retread manufacturer and/or fleet operator guidelines regarding allowable number of and type of repairs. WARNING

C. Selection Criteria for Light Truck DO NOT use flammable cement near fire, flame Radial Steel Body Ply Tire Casings to or any other source of ignition. Explosive force be Retreaded for Use in Steer Axle and/or fire from ignition of cement could cause Applications serious personal injury or death. Light truck radial steel body ply tire casings retreaded for steer axle applications should be appropriately marked on the sidewall C. Cementing (if required) adjacent to the federal retread identification code (see Appendix 5 for federally-required 1. Tires to be cemented should be free of labeling). Note that certain state and/or loose cords or foreign material such as other government agencies may have specific rubber buffings, dirt, oil, etc. requirements. 2. Cementing should be accomplished as soon as possible. Consult the retread V. PROCESSING materials supplier for further information. A. General Statement 3. Exposed steel should be cemented as soon as possible - recommendation is The processes listed below are essential to within 15 minutes after exposure. proper manufacturing of the retread and should be posted in retread plants. Adequate lighting 4. Cemented tires should be kept free (i.e., 200 fc / 2153 lx minimum, 300 fc / 3229 lx from dust and other contaminants. recommended) at the work surface should be provided in the processing area. 5. Cemented tires stored for extended periods should be covered, and may need to be cleaned and/or recemented. B. Buffing 6. Cement, if required, should be handled 1. Buffed tire dimensions should be according to the manufacturer’s appropriate to the tire brand, size, and recommendations. Follow all OSHA type, as well as to the retread system requirements and safety precautions. used. After buffing, wait time to build Contact the individual materials should be minimized in order to avoid manufacturer for a copy of any

22 Retreading Light Truck Radial Steel Body Ply Tires Load Range E and Above Light Truck Radial Steel Body Ply Tires Load Range E and Above Material Safety Data Sheets (MSDS) The shoulder should be cut back at a

needed. Also refer to federal, state slight angle to remove excess rubber RETREADING and local regulations, especially as due to crowding in the smaller tire related to Volatile Organic Compound diameters. (VOC) emissions. f. If splices are required, a 1/8” to 1/4” (3.0 mm-6.0 mm) overlap, depending D. Building/Tread Application on tire size, should be used to allow for a small amount of crowding of 1. If tire cord is exposed on any portion the stock, which serves to apply of the buffed area, it should be coated pressure in holding the two surfaces with a suitable vulcanizing material together. Retreaders should use before applying the tread rubber. either a butt splice or a 45 degree beveled splice. If a hot knife is used 2. Skives should be filled with a repair to make these cuts, the temperature material that is thoroughly stitched of the knife must be below 250°F or extruded into place to eliminate all to prevent scorching, and all cuts trapped air and reinforced if necessary should be wiped with a solvent to (see Recommended Practices for Tire prevent contamination. Repairing). 4. Precure Tread Retreading 3. Mold Cure (Uncured Rubber) Retreading a. Tread rubber should be centered around the buffed circumference a. Apply cushion gum according to the of the tire +/- 1/8” (3.0 mm) from material supplier’s guidelines. Tread the centerline. rubber should be of crown, base, and gauge dimensions as required b. Tread pattern should be matched for matrix (i.e., mold) design and as closely as possible at the splice(s), size, and should provide a minimum if required, while assuring proper of 2/32” (1.5 mm) replacement tread length. undertread. c. Tread ends should be properly NOTE: prepared over the entire surface and Tires with thicker tread depth may require be free of contaminants. If required, additional material. the entire tread end surface should be cemented and gum stripped per b. Tread rubber bonding surfaces are posted procedure. not to be contaminated in any way. d. Tread stitching should be performed c. Tread rubber should be centered in such a way as to avoid trapping around the tire +/- 1/8” (3.0 mm) air, pulling the tread off center, and from the centerline. distorting, folding or wrinkling in the shoulders. d. Tread stitching should be performed in such a way as to avoid trapping air, pulling the tread off center, and E. Curing distorting, folding or wrinkling in the shoulders. 1. Mold Cure (Uncured Rubber) Retreading e. Splices, if any, should be made in such a manner as to ensure a. Tires should be kept free from minimum distortion of the rubber. contamination and stored in such a

23 Retreading Light Truck Radial Steel Body Ply Tires Load Range E and Above Light Truck Radial Steel Body Ply Tires Load Range E and Above manner as to avoid distortion of the service for at least 24 hours since adhesion

uncured rubber. is reduced until the tire has cooled. RETREADING b. Follow manufacturers’ information E. Approved procedures should be followed and/or specifications on curing time, when the tire is mounted and inflated. temperature, pressure, and proper The tire should be inspected at this time curing equipment (i.e., tubes and for any anomalies not previously detected. rims, if used). Follow the OSHA Standards for Servicing Multi-piece and Single-Piece Rim Wheels 2. Precure Tread Retreading (29 C.F.R. § 1910.177, as amended). a. Envelopes or diaphragms, if used, must be leak free. Various testing methods are available, such as inflation or vacuum. b. Wicking, if required, will be used to allow air removal from between the envelope or diaphragm on the enclosed tire surface during cure. c. Follow manufacturers’ information and/or specifications on curing time, temperature, pressure, and proper curing equipment (i.e., tubes and rims, if used).

VI. FINAL INSPECTION A. After curing, the retreader should make a final examination of the tire, preferably while still warm, and while mounted on a spreader under adequate lighting (i.e., 200 fc / 2153 lx minimum, 300 fc / 3229 lx recommended) at the work surface, so that the interior and exterior of the tire is adequately exposed for visual and manual examination. B. The inside of the tire should be checked to ensure that all repairs are properly installed and bonded, and for any internal injuries or conditions that may have been missed during the initial inspection phase. C. The outside of the tire should be checked to ensure that it has been properly molded, cured, trimmed, and has all the required labeling. D. Retreaded tires should not be returned to

24 Light Truck Radial Steel Body Ply Tires Load Range E and Above REPAIRING

Industry Recommended Practices for Tire Repairing Repairing Light Truck Radial Steel Body Ply Tires Load Range E and Above

Contents Page IV. GENERAL STATEMENT ABOUT TIRE REPAIRING I. PURPOSE...... 25 II. SCOPE...... 25 Thorough inspection should be made by a skilled III. INDUSTRY TERMINOLOGY...... 25 technician and should include placing the tire casing IV. GENERAL STATEMENT ABOUT TIRE on a tire inspection machine, or other machine REPAIRING...... 25 capable of spreading the beads under adequate V. INITIAL TIRE INSPECTION...... 26 lighting (i.e., 200 footcandles (fc) / 2153 lux (lx) VI. MINOR RUBBER REPAIRS...... 27 minimum, 300 fc / 3229 lx recommended) at the VII. PUNCTURE REPAIR (NAIL HOLE REPAIR)...28 work surface, so that the interior and exterior of VIII. REINFORCEMENT REPAIRS...... 34 the casing is adequately exposed for visual and IX. SECTION REPAIRS...... 34 manual examination. X. REPAIR FINISHING...... 37 XI. FINAL REPAIR INSPECTION...... 37

I. PURPOSE The purpose of this section is to offer Industry Recommended Practices (IRPs) to members of the industry, for the permanent repairing of light truck radial steel body ply tires, or those with similar material body ply, and a load range of E or above, for highway service. These IRPs are not intended Tire Casing on Inspection Machine to be, and should not be, used as a substitute for the judgment that each industry member should make in establishing and implementing procedures, All casings should be dry and free of all loose training, and supervisory practices for the proper contaminants (e.g., dirt, water, debris, sealants, repair of damaged tires. visual materials, balancing materials, etc.) and/or other foreign materials prior to inspection. All II. SCOPE repair units should be replaced unless they can be determined to be sound and have been properly This section addresses industry terminology, initial installed. Inspection criteria should be posted in tire inspection, acceptable repairing criteria, repair retread plants. finishing, and final inspection practices used in the tire repairing industry. Tire repair facilities should consult new tire manufacturers or material manufacturers III. INDUSTRY TERMINOLOGY regarding the alteration (i.e., retreading or repairing) of speed rated tires. The selection of See Appendix 1 - Common Retread and Repair the repair materials used should be based on the Terminology - A Compendium of Industry Terms. suppliers’ recommendations.

25 Repairing Light Truck Radial Steel Body Ply Tires Load Range E and Above Light Truck Radial Steel Body Ply Tires Load Range E and Above d. Broken belts

CAUTION REPAIRING e. Excessive oxidation (i.e., weather DO NOT MIX PRODUCTS FROM DIFFERENT checking) beyond 2/32” (1.5 mm) REPAIR MATERIAL MANUFACTURERS in depth Follow repair materials manufacturers’ recommendations for installation and instructions. f. Tires with less than 2/32” (1.5 mm) Refer to the information on the product or tread depth (i.e., non-skid) remaining manufacturers’ Material Safety Data Sheets unless retreading is planned (MSDS) and follow guidelines for handling and disposal. g. Radial and/or circumferential cracking V. INITIAL TIRE INSPECTION h. Improper or missing sidewall information Repair procedures require the following: i. Any signs of weakness or non- • Removing damaged material repairable injury (e.g., softness • Preparing the injured area due to contamination from • Filling the injury with a suitable chemical/petroleum products, vulcanizing material or vulcanizing ripples, bulges, porosity, etc.) in the rubber stem sidewall, particularly in the upper • Reinforcing and sealing the repair area sidewall j. Crunching or popping sounds NEVER PERFORM A TIRE REPAIR WITHOUT when flexed REMOVING THE TIRE FROM THE RIM/WHEEL ASSEMBLY FOR INTERNAL INSPECTION. 2. Internal OUTSIDE-IN OR ON-THE-WHEEL TIRE REPAIRS ARE NOT RECOMMENDED. a. Injury to the body ply cord beyond CONTACT TIRE MANUFACTURERS FOR repairable limits SPECIFIC REPAIR PROCEDURES. b. Open inner liner splices which expose cord A. Inspection Criteria for Repairing c. Porous, contaminated from chemical No tires should be accepted for repairing if degradation, or loose inner liners they have any of the following conditions or injuries or which require repairs beyond the d. Loose cords on the inside ply or limits shown in Tables I and IIA (see Tables any evidence of having been run section at the end of this document). underinflated or overloaded

1. External e. Previously installed repairs found to be defective and unrepairable a. Surface cuts which exceed the size of a repairable injury and f. Injuries to the body plies in the penetrate the cord body non-repairable bead area b. Broken, damaged, kinked or g. Flex breaks, X-breaks or impact exposed bead wire bundle breaks c. Damage which requires the repairs h. Non-repairable damage to the to overlap inner liner or bead area on tires identified as tubeless

26 Repairing Light Truck Radial Steel Body Ply Tires Load Range E and Above Light Truck Radial Steel Body Ply Tires Load Range E and Above In addition to checking for non-repairable and maintain its air retention capability.

conditions, check the valve assembly and Consult casing manufacturer for bead area REPAIRING bead area for leaks using a water or leak repair specifications. detection solution, where practical,prior to demounting and deflating the tire. If a leak is found in the valve assembly or in the bead D. Steps for Minor Rubber Repair area, certain repairs may not be possible since the tire will not hold air. The steps listed below are essential to perform a minor rubber repair. Furthermore, along with visual inspection, it is also recommended that some type of nondestructive inspection equipment (e.g., holography, shearography, X-ray, ultrasonics, CAUTION electrostatic, high pressure tester, etc.) be utilized for casing inspection. DO NOT MIX PRODUCTS FROM DIFFERENT REPAIR MATERIAL MANUFACTURERS Follow repair materials manufacturers’ recom- VI. MINOR RUBBER REPAIRS mendations for installation and instructions. Refer to the information on the product or Minor repairs are generally rubber only repairs, manufacturers’ Material Safety Data Sheets (MSDS) and follow guidelines for handling and but should be performed in a full-service repair disposal. facility. See Appendix 1 - Common Retread and Repair Terminology – A Compendium of Industry Terms for a definition of “Full Service Repair Facility”. WARNING A. Spot Repair Radial tires with damage to the body cords DO NOT use flammable solvents near fire, flame or any other source of ignition. Explosive force cannot be spot repaired but should be and/or fire from ignition of solvents could cause considered for section repairing. serious personal injury or death.

B. Inner Liner Repair 1. Probing and Foreign Material Removal Open inner liner splices, cracks which do not expose cord, tool damage or blisters Use a probe to inspect the damage. Remove may be repaired in tubeless tires. Consult any foreign material. casing manufacturer for inner liner repair specifications. 2. Inspection Inspect the injury to determine the extent C. Bead Area Repair of damage. If there is ply body damage, refer to the Section Repairs portion of this Bead area repairs are limited to rubber only document (see section IX). repairs. In no case should a kinked or broken bead be repaired. Tires with evidence of In addition to visual inspection, it is bead area separation or rusting in the body also recommended that some type of plies should be rejected. nondestructive inspection equipment (e.g., holography, shearography, X-ray, Bead area repairs on all tires should restore ultrasonics, electrostatic, high pressure the original contour of the bead. In addition, tester, etc.) be utilized for casing inspection. bead repairs on a tubeless tire should restore

27 Repairing Light Truck Radial Steel Body Ply Tires Load Range E and Above Light Truck Radial Steel Body Ply Tires Load Range E and Above 3. Pre-Cleaning 6. Cementing REPAIRING Remove all contaminants from around the Apply the appropriate cement to the injury. prepared surface with no puddling or streaking. Allow the cement to dry for the NOTE: recommended time. In cold and/or humid 1.) Tires that contain any type of aftermarket climate conditions, extend the drying time puncture sealant(s) may have been damaged as recommended by the manufacturer. as a result of being run underinflated and/or overloaded, and should be inspected accordingly. 7. Filling 2.) Tires that are manufactured with puncture Fill the injury with a suitable vulcanizing sealing capabilities require specialized repair material. techniques. The tire and/or sealant manufacturers should be contacted for recommendations. It may 8. Curing be necessary to repeat step 3, pre-cleaning, to ensure that the repair area is free of contaminants. Cure the repair for the specified time, temperature, and pressure according to the 4. Buffing equipment and materials manufacturers’ recommendations. For chemically activated Buff the injury to achieve a uniform TRMG repairs, allow sufficient time for curing as BT1 or BT2 buff texture for all repairs recommended by the manufacturer. (see RP 01/02-23 “BTS6 - Standard Buffing Textures for Tire Retreading and Repairing”). Remove all damaged or loose material. VII. PUNCTURE REPAIR (NAIL HOLE REPAIR) Texturize the repair area with a low-speed (i.e., 5,000 rpm maximum) buffer and Prior to demounting and deflating the tire, check appropriate buffing tool while keeping the the valve and outer surface for leaks using a water repair area as small as possible. or leak detection solution, where practical. If a leak is found in the valve assembly or in the bead 5. Cleaning area, a puncture repair may not be possible since the tire will not hold air. If no leak is found in valve Remove any rubber dust and contaminants assembly or bead area, proceed by marking the from the buffed area with a fine wire brush injury, totally deflate, and demount the tire. and vacuum to provide a clean, dry surface. Do not use compressed air to clean Repair procedures require the following: bonding surfaces because the unfiltered air lines may contain contaminants such • Removal of damaged material as oil and moisture, which can reduce • Preparing the injured area adhesion. • Filling the injury with a suitable vulcanizing material or vulcanizing rubber stem WARNING • Reinforcing and sealing the repair area

DO NOT use flammablecement near fire, flame NEVER PERFORM A TIRE REPAIR WITHOUT or any other source of ignition. Explosive force REMOVING THE TIRE FROM THE RIM/WHEEL and/or fire from ignition of cement could cause ASSEMBLY FOR INTERNAL INSPECTION. serious personal injury or death. OUTSIDE-IN OR ON-THE-WHEEL TIRE REPAIRS ARE NOT RECOMMENDED. CONTACT TIRE MANUFACTURERS FOR SPECIFIC REPAIR PROCEDURES.

28 Repairing Light Truck Radial Steel Body Ply Tires Load Range E and Above Light Truck Radial Steel Body Ply Tires Load Range E and Above Determine the extent and location of any injuries.

Repair shops should consult the tire manufacturer REPAIRING and repair material manufacturer regarding the alteration (i.e., retreading or repairing) of speed rated tires.

NOTE: Not all tires can be repaired. Specific repair limits should be based on recommendations or repair policies of the tire manufacturer and/or type of tire service (e.g., service description, run-flat FIGURE 1 technology, commercial service applications, etc.).

A. Light Truck Radial Steel Body Ply Tire DO NOT make repairs where the injury damage Puncture Repair extends into the shoulder/belt edge area OR where the injury extends at an angle into the shoulder area. Tire puncture repairs should be limited to the tread area only and should not exceed 3/8” (10.0 mm) in diameter after preparation. B. Steps for Puncture Repair Refer to tire manufacturer for recommended repair limits. The steps listed below are essential to repair a puncture in light truck radial steel body ply Figure 1 represents a light truck radial steel tires. See tire repair images below and on the body ply tire (load range E and above) and following pages. indicates that puncture repairs are limited to the tread area only, as generally depicted in the graphic.

PUNCTURE REPAIR Mark and Probe the Injury

Place Tire on Inspection Machine Mark the Injury - Outside Tire Remove Penetrating Object

Mark the Injury - Inside Tire Probe the Injury - Outside Tire Probe the Injury - Inside Tire

29 Repairing Light Truck Radial Steel Body Ply Tires Load Range E and Above Light Truck Radial Steel Body Ply Tires Load Range E and Above NOTE:

CAUTION 1.) Tires that contain any type of aftermarket REPAIRING puncture sealant(s) may have been damaged DO NOT MIX PRODUCTS FROM DIFFERENT as a result of being run underinflated and/or REPAIR MATERIAL MANUFACTURERS overloaded, and should be inspected accordingly. Follow repair materials manufacturers’ recommendations for installation and instructions. 2.) Tires that are manufactured with puncture Refer to the information on the product or sealing capabilities require specialized repair manufacturers’ Material Safety Data Sheets techniques. The tire and/or sealant manufacturers (MSDS) and follow guidelines for handling and should be contacted for recommendations. It may disposal. be necessary to repeat step 2, pre-cleaning, to ensure that the repair area is free of contaminants.

3. Preparation of the Injury WARNING When possible, drill the injury from the inside a minimum of three times with the DO NOT use flammable solvents near fire, flame or any other source of ignition. Explosive force appropriate carbide cutter on a low speed and/or fire from ignition of solvents could cause (i.e., 1,200 rpm maximum) air/electric drill, serious personal injury or death. or other suitable tool, following the angle of penetration. Tools used must remove the damaged steel and create a round hole. Repeat this process a minimum of 1. Probing and Foreign Material Removal three times from the outside of the tire to ensure complete damage removal, being Probe the injury with a tire probe to careful not to elongate the hole. determine the angle and size of penetration. Inspect and remove any foreign material Use a probe to check for any splits in the that has penetrated the tire. radial plies surrounding the injury. Remove any additional damage found. 2. Pre-Cleaning 4. Inspection Remove all contaminants from around the injury. Inspect the injury, and consult the tire manufacturer regarding injury limits. In addition, inspect the prepared injury for inner liner splits. If present, this is no PUNCTURE REPAIR cont. Pre-Clean and Drill

Scrape Away Contaminants Drill the Injury - Inside Tire Drill the Injury - Outside Tire

30 Repairing Light Truck Radial Steel Body Ply Tires Load Range E and Above Light Truck Radial Steel Body Ply Tires Load Range E and Above

PUNCTURE REPAIR cont. Repair Unit Selection REPAIRING

One Piece Repair Unit Two Piece Repair Unit

longer a puncture repair. Refer to the recommendations. Center the unit over Section Repair portion of this document the injury and outline an area about 1/2” (see section IX.B.). (13.0 mm) larger than the repair unit, to ensure that crayon marks are not removed 5. Repair Unit Selection when buffing. Select the appropriate repair unit For injuries with an angle greater than 25 based on repair material manufacturer degrees, depending on repair manufacturer, use a two-piece repair unit system.

PUNCTURE REPAIR cont. Buff and Clean Repair Area for a One-Piece Repair Unit

Buff the Repair Area Brush the Repair Area Vacuum the Repair Area

Buff and Clean Area for a Two-Piece Repair Unit

Buff the Repair Area Brush the Repair Area Vacuum the Repair Area

31 Repairing Light Truck Radial Steel Body Ply Tires Load Range E and Above Light Truck Radial Steel Body Ply Tires Load Range E and Above 6. Inner Liner Buffing surfaces because the unfiltered air lines

may contain contaminants such as oil and REPAIRING To prevent contamination and preserve moisture, which can reduce adhesion. the outline, buff within the marked area thoroughly and evenly using a low speed (i.e., 5,000 rpm maximum) buffer with a fine wire brush or gritted rasp. Take care WARNING not to expose or damage the tire casing body (ply) cords. Buff to a velvet surface; DO NOT use flammablecement near fire, flame TRMG BT1 or BT2 texture. or any other source of ignition. Explosive force and/or fire from ignition of cement could cause 7. Cleaning serious personal injury or death. Remove any rubber dust and contaminants from the buffed area with a fine wire brush 8. Cementing and vacuum to provide a clean, dry surface. Do not use compressed air to clean bonding Apply appropriate cement to the buffed surface and, if required, to the back of the

PUNCTURE REPAIR cont. Cement and Install One-Piece Repair Unit

Cement the Injury Channel Cement the Buffed Area Install the Repair Unit

Pull Repair Unit Stem Through Tire Press Repair Unit into Place Stitch the Repair Unit

Apply Repair Sealant Cut the Stem - Outside Tire Buff the Cut Stem

32 Repairing Light Truck Radial Steel Body Ply Tires Load Range E and Above Light Truck Radial Steel Body Ply Tires Load Range E and Above repair unit. Allow the cement to dry for the 10. Repair Unit Installation

recommended time. While drying, the tire REPAIRING should be rotated so that the injury is not Repair units are to be installed while the positioned at the bottom of the tire. beads of the tire are in a relaxed position. Align the repair unit according to the DO NOT use forced air or an outside heat source markings on the repair unit. Avoid trapping to accelerate drying time. Refer to repair materials air and/or possible bridging of the unit as manufacturer recommendations. it is installed.

9. Fill the Injury a. When using a one-piece repair unit, cement the injury channel, insert If using an uncured/suitable vulcanizing the stem from the inside of the tire, material or vulcanizing rubber stem, fill and pull through until the base of the injury with the appropriate material. the repair unit is snug against the prepared and cemented surface of the inner liner.

PUNCTURE REPAIR cont. Cement and Install Two-Piece Repair Unit

Cement the Injury Channel Insert the Stem Cut the Stem - Inside Tire

Cement the Buffed Area Install the Repair Unit Stitch the Repair Unit

Apply Repair Sealant Cut the Stem - Outside Tire Buff the Cut Stem

33 Repairing Light Truck Radial Steel Body Ply Tires Load Range E and Above Light Truck Radial Steel Body Ply Tires Load Range E and Above b. When using a two-piece repair unit VIII. REINFORCEMENT REPAIRS

(i.e., separate repair unit and filler REPAIRING stem), cement the injury channel and Determine the extent and location of any injuries. fill the injury from the inside with Repair shops should consult the tire manufacturer a suitable vulcanizing rubber stem and repair material manufacturer regarding specific designed for that size injury. Without repair limits. These limits should be based on stretching the stem, cut/trim the recommendations of the tire manufacturer, repair excess material inside the tire, and materials manufacturer, and type of tire service. buff the stem flush with the inner liner to accommodate the appropriate size A. Steps for Reinforcement Repairs repair unit. Refer to the Section Repairs portion of this Remember, for both types of repair units, document (see section IX.B., Steps for Section DO NOT cement the stem. Instead, cement Repairs). the injury channel. 11. Stitching CAUTION For all methods, stitch the entire repair unit starting from the center, and work DO NOT MIX PRODUCTS FROM DIFFERENT outwards to the edges. Check for proper REPAIR MATERIAL MANUFACTURERS installation. Cut the fill material flush with Follow repair materials manufacturers’ recom- the outer tread surface making sure not to mendations for installation and instructions. stretch or pull the stem while cutting. If the Refer to the information on the product or stem is not flush with tread after cutting, manufacturers’ Material Safety Data Sheets buff lightly until it is level with tread. (MSDS) and follow guidelines for handling and disposal. 12. Curing The repair unit and uncured/suitable vulcanizing material or vulcanizing rubber WARNING stem, must be cured completely. When using a spotter, section mold or curing DO NOT use flammablesolvents near fire, flame chamber, follow the manufacturers’ or any other source of ignition. Explosive force recommendations. Also follow the and/or fire from ignition of solvents could cause manufacturers’ recommendations for serious personal injury or death. calculating cure time. Cure the repair for the specified time, temperature, and pressure according to the equipment and materials manufacturers’ recommendations. For IX. SECTION REPAIRS chemically activated repairs, allow sufficient time for curing as recommended by the Determine the extent and location of any injuries. manufacturer. Repair shops should consult the tire manufacturer and repair material manufacturer regarding specific 13. Inspect Repair Areas repair limits. These limits should be based on recommendations of the tire manufacturer, repair If the buffed area extends beyond the repair materials manufacturer, and type of tire service. unit, look for signs of tire casing body cords. A. Section Repair Limits Apply repair sealant to the over-buffed area and the edge of the repair unit. A patch only There are several methods of section repairing or a plug (stem) only is not a proper puncture tires. The method is dependent on the repair. (See section X, Repair Finishing.) materials and equipment being used.

34 Repairing Light Truck Radial Steel Body Ply Tires Load Range E and Above Light Truck Radial Steel Body Ply Tires Load Range E and Above Final measurements to determine repairability as a result of being run underinflated and/or

and repair unit selection should be made overloaded, and should be inspected accordingly. REPAIRING when all of the injury has been removed. 2.) Tires that are manufactured with puncture sealing capabilities require specialized repair B. Steps for Section Repairs techniques. The tire and/or sealant manufacturers should be contacted for recommendations. It may The steps listed below are essential to make be necessary to repeat step 3, pre-cleaning, to a section repair in a tire. ensure that the repair area is free of contaminants.

4. Skiving CAUTION Using a low-speed (i.e., 5,000 rpm maximum) buffer and appropriate buffing DO NOT MIX PRODUCTS FROM DIFFERENT texture tool, remove all damaged rubber REPAIR MATERIAL MANUFACTURERS above the steel cables, taking care to keep the injured area as small as possible. Use Follow repair materials manufacturers’ recommendations for installation and instructions. an appropriate texture tool on a low-speed Refer to the information on the product or (i.e., 5,000 rpm maximum) buffer to buff manufacturers’ Material Safety Data Sheets away remaining rubber and very lightly (MSDS) and follow guidelines for handling and expose only tread belt cables believed disposal. to be damaged (i.e., just until they are visible). All damaged loose body ply must be trimmed back to solid rubber. Buff with a low-speed (i.e., 5,000 rpm maximum) WARNING buffer and appropriate buffing texture tool to achieve a uniform TRMG BT2 or BT3 texture. Always probe the repair area after DO NOT use flammablesolvents near fire, flame or any other source of ignition. Explosive force damage removal to ensure that no cuts or and/or fire from ignition of solvents could cause separations remain in the tire. serious personal injury or death. 5. Repair Unit Selection Select the appropriate repair unit based 1. Probing and Foreign Material Removal on the construction of the tire and the size of the damage to the body cords or cables. Use a probe to inspect and remove any Final measurements should be made foreign material that has penetrated the tire. when the entire injury has been removed. Refer to Table I and related diagrams for 2. Inspection Maximum Injury Limits (see Tables section at the end of this document), and to repair Inspect, mark, and measure all injuries to materials manufacturers’ charts for proper determine repairability and the extent of repair unit selection. damage. 6. Inner Liner Buffing 3. Pre-Cleaning Buff the area for the repair unit with a low Remove all contaminants from around the speed (i.e., 5,000 rpm maximum) buffer injury. and appropriate buffing texture tool to achieve a uniform TRMG BT1 or BT2 buffed NOTE: texture. The buffed area should be slightly 1.) Tires that contain any type of aftermarket larger than the repair unit. puncture sealant(s) may have been damaged

35 Repairing Light Truck Radial Steel Body Ply Tires Load Range E and Above Light Truck Radial Steel Body Ply Tires Load Range E and Above NOTE: 9. Fill the Injury

If a suitable vulcanizing material or vulcanizing REPAIRING rubber stem is used to fill an injury, it must be Fill the injury with an uncured/suitable installed before buffing. vulcanizing material or vulcanizing rubber stem. Cement the injury channel and fill the injury from the inside with a suitable vulcanizing 10. Repair Unit Installation material or vulcanizing rubber stem. Without stretching the stem, trim the excess material Repair units are to be installed with the inside the tire, and buff the stem flush beads of the tire in the relaxed position. with the inner liner to accommodate the Align the repair unit according to markings appropriate size repair unit. on the repair unit.

7. Cleaning a. When using a one-piece chemical section repair unit, insert the stem Remove any rubber dust and contaminants from the inside of the tire and pull from the buffed area with a fine wire brush through until the base of the repair and vacuum to provide a clean, dry surface. unit is snug against the prepared and Do not use compressed air to clean bonding cemented surface of the inner liner. surfaces because the unfiltered air lines may contain contaminants such as oil and b. Stitch the entire repair unit starting moisture, which can reduce adhesion. from the center, and move outwards to the edges. Check for proper installation. Inspect repair area. If the buffed area extends beyond the repair unit, look for signs of tire WARNING casing body cords.

DO NOT use flammablecement near fire, flame DO NOT continue the repair if the buffed or any other source of ignition. Explosive force area exposes radial ply cords. and/or fire from ignition of cement could cause serious personal injury or death. c. If recommended by repair manufacturer, apply repair sealant to the over-buffed area and the edge of 8. Cementing the repair unit. Apply the appropriate cement to the buffed 11. Curing surface depending on the repair method being used. Also apply the appropriate The repair unit and uncured/suitable cement to the back of the repair unit if vulcanizing material, or vulcanizing rubber required. The cement should be applied stem, must be cured completely. When evenly to all surfaces with no puddling or using a spotter, section mold or curing streaking. Allow the cement to dry for the chamber, follow the manufacturers’ recommended time. In cold and/or humid recommendations. Also follow the repair climate conditions, extend the drying time material and equipment manufacturers’ as recommended by the manufacturer. recommendations for calculating cure time. Cure the repair for the specified time, DO NOT use forced air or outside heat source to temperature, and pressure. For chemically accelerate drying time. Refer to repair materials activated repair unit application, allow manufacturer recommendations. sufficient time for curing as recommended by the manufacturer.

36 Repairing Light Truck Radial Steel Body Ply Tires Load Range E and Above Light Truck Radial Steel Body Ply Tires Load Range E and Above 12. Inspect Repair Areas B. Criteria for Repair Inspection REPAIRING If the buffed area extends beyond the repair The steps listed below are essential for proper unit, look for signs of tire casing body cords. inspection of a repaired tire. During the inspection process, the same steps used in Initial Tire Inspection should be followed in X. REPAIR FINISHING the Final Repair Inspection. A. General Repair Finishing 1. Inside Inspection Finishing is necessary to ensure satisfactory The inside of the tire should be checked performance and appearance of the repaired to ensure that all repairs are properly tire. Repair identification (typically the DOT-R installed and bonded, and for any internal Plant Code or other internal codes) and dating injuries or conditions that may have been should be placed on or next to the repair missed during the initial inspection phase. unit. (See section XI.B., Criteria for Repair Inspection.) 2. Outside Inspection The outside of the tire should be checked B. Steps for Repair Finishing to ensure that it has been properly molded, cured, trimmed, and has all the required The steps listed below are essential for proper labeling. completion of a tire repair. 3. Approved procedures should be 1. Buffing followed when the tire is mounted and inflated. The tire should be inspected Buff the cured rubber filler material or trim at this time for any anomalies not the precured repair stem to the original previously detected. Follow the OSHA contour and appearance of the tire. The Standards for Servicing Multi-Piece surface of the rubber repair material may and Single-Piece Rim Wheels (29 C.F.R. not extend over 2/32” (1.5 mm) above the § 1910.177). surrounding surface. (See section XI.B., Criteria for Repair Inspection.) 4. Section repaired tires should not be returned to service for a minimum of 2. Tread Design 24 hours after curing, when they have reached ambient air temperature. Restore tread design in the crown area.

XI. FINAL REPAIR INSPECTION A. General Repair Inspection Conduct a final examination of the tire while it is mounted on a spreader under adequate lighting (i.e., 200 fc / 2153 lx minimum, 300 fc / 3229 lx recommended) at the work surface. If heat is used to cure the repair, conduct the inspection while the repair is still warm.

37 Heavy Radial Truck, and Bus Tires Medium Truck, RETREADING

Industry Recommended Practices for Tire Retreading Retreading Medium Truck, Heavy Radial Truck, and Bus Tires

Contents Page IV. INITIAL CASING INSPECTION AND SELECTION FOR RETREADING I. PURPOSE...... 38 II. SCOPE...... 38 A. General Statement III. INDUSTRY TERMINOLOGY...... 38 IV. INITIAL CASING INSPECTION AND Thorough inspection should be made by a SELECTION FOR RETREADING...... 38 skilled operator and should include placing V. PROCESSING...... 40 the tire casing on a tire inspection machine, VI. FINAL INSPECTION...... 44 or other machine capable of spreading the beads under adequate lighting (i.e., 200 footcandles (fc) / 2153 lux (lx) minimum, 300 fc / 3229 lx recommended) at the work surface so that the interior and exterior of the I. PURPOSE casing is adequately exposed for visual and manual examination. See casing inspection The purpose of this section is to offer Industry images on the following page. Recommended Practices (IRPs) to members of the industry, for the manufacturing of retreaded medium truck, heavy radial truck, and bus tires for highway service. These IRPs are not intended to be, and should not be, used as a substitute for the judgment that each industry member should make in establishing and implementing procedures, training, and supervisory practices for the proper inspection, selection, and retreading of worn tires.

II. SCOPE Tire Casing on Inspection Machine This section addresses industry terminology, initial casing inspection and selection for retreading, processing, and final inspection guidelines used in All casings should be dry and free of all the tire retreading industry. loose contaminants (e.g., dirt, water, debris, sealants, visual materials, balancing materials, etc.) and/or other foreign materials prior to III. INDUSTRY TERMINOLOGY inspection. All repair units should be replaced unless they can be determined to be sound See Appendix 1 - Common Retread and Repair and have been properly installed. Inspection Terminology - A Compendium of Industry Terms. criteria should be posted in retread plants.

38 Retreading Medium Truck, Heavy Radial Truck, and Bus Tires Heavy Radial Truck, and Bus Tires Medium Truck,

INITIAL CASING INSPECTION RETREADING

Inspect Inside of Casing Mark Inspection Starting Point Inspect Outside of Casing

Probe Injury Remove Foreign Material Casing on Shearography Machine

In addition to visual inspection, it is b. Tread separations which cannot be also recommended that some type of removed during buffing nondestructive inspection equipment (e.g., holography, shearography, X-ray, ultrasonics, c. Broken, damaged, kinked or electrostatic, high pressure tester, etc.) be exposed bead wire bundle utilized for casing inspection. d. Excessive oxidation (i.e., weather checking) extending to the body B. Inspection Criteria for Medium Truck, plies or deeper than 2/32’’ (1.5 mm) Heavy Radial Truck, and Bus Casings Used on the Highway e. Tires worn to exposed belt wires on more than 10% of the worn tire No medium truck, heavy radial truck or bus circumference, unless a protector tire casings should be accepted for retreading belt is to be removed or damaged having any of the following conditions or belts are to be replaced injuries which require repairs beyond the limits of the IRPs or beyond the limits outlined f. Circumferential cracking in Tables I and II-A (see Tables section at the end of this document). Medium truck, heavy g. Tires with rust or corrosion beyond radial truck, and bus tires should meet the repairable limits labeling requirements outlined in section VI.C. of this document. h. Any signs of weakness or non- repairable injury (e.g., softness 1. External due to contamination from chemical/petroleum products, a. Ply separation beyond repairable ripples, bulges, porosity, etc.) in the limits

39 Retreading Medium Truck, Heavy Radial Truck, and Bus Tires Heavy Radial Truck, and Bus Tires

sidewall, particularly in the upper sidewall adjacent to the federal retread Medium Truck, sidewall identification code (see Appendix 5 for RETREADING federally-required labeling). Note that certain i. Crunching or popping sounds state and/or other government agencies may when flexed have specific requirements.

j. Surface cuts which exceed the NOTE: size of a repairable injury and Federal Motor Carrier Safety Regulations, 9C.F.R. penetrate the cord body § 393.75 (d), specify that “No bus shall be operated with regrooved, recapped or retread- k. Radial ply cracking ed tires on the front wheels.” l. Improper labeling D. Zipper Damage Indicators 2. Internal Indications of zipper damage include any a. Injuries to the body plies in the signs of weakness or non-repairable injury non-repairable bead area (e.g., ripples, bulges, porosity, softness, etc.) in the sidewall, particularly the upper sidewall. b. Loose cords on the inside ply Steel belted radial tires exhibiting such or evidence of having been run conditions should be rejected and scrapped. underinflated or overloaded 1. Cuts, snags or chips exposing body c. Non-repairable damage to the cords or steel inner liner or bead area on tires identified as tubeless 2. Distortions or undulations (ripples and/or bulges) visible when using d. Open inner liner splices which an indirect light source which will expose cord produce shadows left by any sidewall irregularities e. Flex breaks, X-breaks or impact breaks 3. Creasing, wrinkling, cracking or discoloration of the inner liner f. Porous, contaminated from chemical degradation, or loose 4. Soft spot(s) in the sidewall flex area inner liners 5. Protruding filaments indicating broken g. Previously installed repairs found cords to be defective and unrepairable 6. Any popping sound when feeling for h. Suspected of potential zipper soft spots or when rolling the tire damage (see section VI.D. Zipper Damage Indicators) V. PROCESSING C. Selection Criteria for Medium Truck, A. General Statement Heavy Radial Truck, and Bus Tire Casings to be Retreaded for Use in The processes listed below are essential to Steer Axle Applications proper manufacturing of the retread and should be posted in retread plants. Adequate lighting Medium truck, heavy radial truck or bus tire (i.e., 200 fc / 2153 lx minimum, 300 fc / 3229 lx casings retreaded for steer axle applications, recommended) at the work surface should be should be appropriately marked on the provided in the processing area.

40 Retreading Medium Truck, Heavy Radial Truck, and Bus Tires Heavy Radial Truck, and Bus Tires Medium Truck,

BUFFING AND INJURY REMOVAL RETREADING

Casing on a Buffing Machine Buff Tread Surface Remove Injury - Tread Area

Remove Injury - Shoulder Fill Skives Fill Skives

B. Buffing and penetrations of tread cuts skived to remove injured material. 1. Buffed tire dimensions should be appropriate to the tire brand, size, and 4. Any damage larger than 3/8” (10.0 type, as well as to the retread system mm) to the first working belt (i.e., belt used. After buffing, wait time to build closest to radial ply) requires a section should be minimized in order to avoid repair (refer to Appendix 2). Damage contamination or oxidation. If wait to the #2 or #3 belt greater than 3/8” time exceeds two hours, the surface (10.0 mm) may require a section repair. should be brushed to remove possible Consult the new tire manufacturer contamination or oxidation before and/or the tire repair materials applying cement or cushion. manufacturer for further information. 2. The tread surface, which is to receive the new rubber, should be prepared to a symmetrical profile and proper texture. WARNING All frayed cord should be trimmed back DO NOT use flammablecement near fire, flame to solid rubber. The buffed surface or any other source of ignition. Explosive force should be free from contamination and/or fire from ignition of cement could cause and have a texture equivalent to a serious personal injury or death. TRMG BT3 or BT4 (see RP 01/02-23 “BTS6 - Standard Buffing Textures for Tire Retreading and Repairing”). C. Cementing (if required) 3. The buffed surface should be examined 1. Tires to be cemented should be free of

41 Retreading Medium Truck, Heavy Radial Truck, and Bus Tires Heavy Radial Truck, and Bus Tires

loose cords or foreign material such as 2. Skives should be filled with a repair Medium Truck, rubber buffings, dirt, oil, etc. material that is thoroughly stitched RETREADING or extruded into place to eliminate all 2. Cementing should be accomplished as trapped air and reinforced if necessary soon as possible. Consult the retread (see Recommended Practices for Tire materials supplier for additional Repairing). information. 3. Mold Cure (Uncured Rubber) 3. Exposed steel should be cemented as Retreading soon as possible - recommendation is within 15 minutes after exposure. a. Apply cushion gum according to material suppliers’ guidelines. 4. Cemented tires should be kept free Tread rubber should be of crown, from dust and other contaminants. base, and gauge dimensions as required for matrix (i.e., mold) 5. Cemented tires stored for extended design and size in which the tire periods should be covered, and may is to be cured, and should provide need to be cleaned and/or recemented. a minimum of 3/32” (2.5 mm) replacement undertread. 6. Cement, if required, should be handled according to manufacturers’ NOTE: recommendations. Follow all OSHA Tires with thicker tread depth may require requirements and safety precautions. additional material. Contact the individual materials manufacturer for a copy of any Material b. Tread rubber bonding surfaces are Safety Data Sheets (MSDS) needed. not to be contaminated in any way. Also refer to federal, state and local regulations, especially as related to c. Tread rubber should be centered Volatile Organic Compound (VOC) around the tire +/- 1/8” (3.0 mm) emissions. from the centerline. d. Tread stitching should be performed D. Building/Tread Application in such a way as to avoid trapping air, pulling the tread off center, and 1. If tire cord is exposed on any portion distorting, folding or wrinkling in of the buffed area, it should be coated the shoulders. with a suitable vulcanizing material before applying the tread rubber.

MOLD CURE RETREADING

Stock Rubber - Extruder Application Apply Rubber to Buffed Casing Apply Rubber to Buffed Casing

42 Retreading Medium Truck, Heavy Radial Truck, and Bus Tires Heavy Radial Truck, and Bus Tires

e. Splices, if any, should be made 4. Precure Tread Retreading Medium Truck, in such a manner as to ensure RETREADING minimum distortion of the rubber. a. Tread rubber should be centered No heavy bulging or open light around the buffed circumference joints. The shoulder area should be of the tire +/- 1/8” (3.0 mm) from cut back at a slight angle to remove the centerline. excess rubber due to crowding in the smaller tire diameters. b. Tread pattern should be matched as closely as possible at the splice(s), f. If splices are required, a 1/8” to if required, while assuring proper 1/4” (3.0 mm-6.0 mm) overlap, tread length. depending on tire size, should be used to allow for a small amount of c. Tread ends should be properly crowding of the stock, which serves prepared over the entire surface and to apply pressure in holding the be free of contaminants. If required, two surfaces together. Retreaders the entire tread end surface should should use either a butt splice or be cemented and gum stripped per a 45 degree beveled splice. If a posted procedure. hot knife is used to make these cuts, the temperature of the knife d. Tread stitching should be performed must be below 250°F to prevent in such a way as to avoid trapping scorching, and all cuts should be air, pulling the tread off center, and wiped with a solvent to prevent distorting, folding or wrinkling in contamination. the shoulders.

PRECURE TREAD RETREADING

Apply Tread to Buffed Casing Cut Tread Ends to Proper Length Cement Tread Ends

Match Tread Pattern at the Splice Staple Seam Casing Ready for Curing Chamber

43 Retreading Medium Truck, Heavy Radial Truck, and Bus Tires Heavy Radial Truck, and Bus Tires

E. Curing C. The outside of the tire should be checked Medium Truck, (See images on the following page.) to ensure that it has been properly RETREADING molded, cured, trimmed and has all the 1. Mold Cure (Uncured Rubber) required labeling, including as federally Retreading required in 49 C.F.R. Part 574 – Tire Identification and Record Keeping (as a. Tires should be kept free from amended). Retreads used in certain contamination and stored in such states may require additional labeling a manner as to avoid distortion of indicating that a tire has been retreaded the uncured rubber. in accordance with this retreading standard, and whether or not it qualifies b. Follow manufacturers’ information for use in steer axle applications (see and/or specifications on curing time, Appendices at the end of this document temperature, pressure, and proper and Reference Documents list following curing equipment (i.e., tubes and the Table of Contents). rims if used). D. Retreaded tires should not be returned 2. Precure Tread Retreading to service for at least 24 hours since adhesion is reduced until the tire has a. Envelopes or diaphragms, if used, cooled. must be leak free. Various testing methods are available, such as E. Approved procedures should be followed inflation or vacuum. when the tire is mounted and inflated. The tire should be inspected at this b. Wicking, if required, will be used time for any anomalies not previously to allow air removal from between detected. Follow the OSHA Standards the envelope or diaphragm on the for Servicing Multi-piece and Single- enclosed tire surface during cure. Piece Rim Wheels (29 C.F.R. § 1910.177, as amended). c. Follow manufacturers’ information and/or specifications on curing time, temperature, pressure, and proper curing equipment (i.e., tubes and rims if used).

44 Retreading Medium Truck, Heavy Radial Truck, and Bus Tires Heavy Radial Truck, and Bus Tires

CURING Medium Truck, Mold Cure Retreading RETREADING

Place Casing in Tire Curing Press Casing in Tire Curing Press Mold Cure Complete

CURING Precure Retreading

Apply Envelope Casing in Envelope Casings Ready for Curing Chamber

Remove Air from Envelope Casings Placed in Curing Chamber Casings Ready for Envelope Removal

Envelope Removal Envelope Removal Envelope Removal

45 Heavy Radial Truck, and Bus Tires Medium Truck, REPAIRING

Industry Recommended Practices for Tire Repairing Repairing Medium Truck, Heavy Radial Truck, and Bus Tires

Contents Page IV. GENERAL STATEMENT ABOUT TIRE REPAIRING I. PURPOSE...... 46 II. SCOPE...... 46 Thorough inspection should be made by a skilled III. INDUSTRY TERMINOLOGY...... 46 technician and should include placing the tire IV. GENERAL STATEMENT ABOUT TIRE casing on a tire inspection machine, or other REPAIRING...... 46 machine capable of spreading the beads under V. INITIAL TIRE INSPECTION...... 47 adequate lighting (i.e., 200 footcandles (fc) / 2153 VI. MINOR RUBBER REPAIRS...... 48 lux (lx) minimum, 300 fc / 3229 lx recommended) at VII. PUNCTURE REPAIR (NAIL HOLE REPAIR).....50 the work surface, so that the interior and exterior VIII. REINFORCED SHOULDER REPAIR...... 55 of the casing is adequately exposed for visual and IX. REINFORCEMENT REPAIRS...... 56 manual examination. X. SECTION REPAIRS...... 56 XI. REPAIR FINISHING...... 60 XII. FINAL REPAIR INSPECTION...... 61

I. PURPOSE The purpose of this section is to offer Industry Recommended Practices (IRPs) to members of the industry, for the permanent repairing of medium truck, heavy radial truck, and bus tires for highway service. These IRPs are not intended to be, and should not be, used as a substitute Tire Casing on Inspection Machine for the judgment that each industry member should make in establishing and implementing procedures, training, and supervisory practices for the proper repair of damaged tires. All casings should be dry and free of all loose contaminants (e.g., dirt, water, debris, sealants, II. SCOPE visual materials, balancing materials, etc.) and/or other foreign materials prior to inspection. This section addresses industry terminology, initial tire inspection, acceptable repairing criteria, repair All repair units should be replaced unless they finishing, and final inspection practices used in the can be determined to be sound and have been tire repairing industry. properly installed. Inspection criteria should be posted in retread plants. The selection of the repair materials used should be based on III. INDUSTRY TERMINOLOGY the suppliers’ recommendations. See Appendix 1 - Common Retread and Repair Terminology - A Compendium of Industry Terms.

46 REPAIRING Medium Truck, Heavy Radial Truck, and Bus Tires information in depth on more than 10% of the worn tire tire worn the of 10% than more on circumference, unless a protector cracking checking) beyond 2/32” (1.5 mm) mm) (1.5 2/32” beyond checking) cord chemical/petroleum products, expose cord degradation, or loose inner liners inner loose or degradation, due to contamination from from contamination to due unless retreading is planned to overlap; requires more than one one than more requires overlap; to sidewall, particularly in the upper upper the in particularly sidewall, sidewall limits repairable limits damaged or be removed to is belt replaced be to belts are tread depth (non-skid) remaining remaining (non-skid) depth tread repair to the same radial body ply body ply radial same the to repair repairable injury (e.g., softness softness (e.g., injury repairable the in etc.) porosity, bulges, ripples, Separations beyond repairable repairable beyond Separations Crunching or popping sounds Open inner liner splices which which splices liner inner Open when flexed Porous, contaminated from chemical contaminated Porous, Radial and/or circumferentialRadial and/or sidewall missing or Improper Excessive oxidation (i.e., weather weather (i.e., oxidation Excessive repairs the requires which Damage Damage exposing the radial ply tire body in the bead area bead the in body tire Any signs of weakness or non- or weakness of signs Any Tires with rust or corrosion beyond beyond corrosion or rust with Tires wires belt exposed to worn Tires Tires with less than 2/32” (1.5 mm) mm) (1.5 2/32” than less with Tires

g. i. e. Internal d. j. b. k. l. m. n. h. f. a.

2. 47 - CAUTION cord body exposed bead wire bundle wire bead exposed a repairable injury and penetrate the penetrate and injury a repairable Surface cuts which exceed the size of size the exceed Surface cuts which Broken belts Broken, damaged, kinked or or kinked damaged, Broken, ARE NOT RECOMMENDED. NOT ARE

SPECIFIC REPAIR PROCEDURES. REPAIR SPECIFIC Repairing Medium Truck, Heavy Radial Truck, and Bus Tires Bus and Truck, Heavy Radial Truck, Medium Repairing c. External b. a.

Inspection Criteria forRepairing ASSEMBLY FOR INTERNAL INSPECTION. FOR INTERNAL ASSEMBLY 1. CONTACT TIRE MANUFACTURERS FOR MANUFACTURERS TIRE CONTACT

REPAIR MATERIAL MANUFACTURERS MATERIAL REPAIR rubber stem Removing damaged material Preparing the injured area Filling the injury with a suitable Reinforcing and sealing the area vulcanizing material or vulcanizing NEVER PERFORM A TIRE REPAIR WITHOUT REPAIR A TIRE PERFORM NEVER

REMOVING THE TIRE FROM THE RIM/WHEEL THE RIM/WHEEL FROM THE TIRE REMOVING injuries, or which require repairs beyond the the beyond repairs require which or injuries, section at the end of this document). this of end the sectionat they they have any of the conditionsor following Tables (see II-A I and Tables in shown limits INITIAL TIRE INSPECTION TIRE INITIAL No No tiresshould beaccepted for repairing if A. DO NOT MIX PRODUCTS DIFFERENT FROM • • • • OUTSIDE-IN OR ON-THE-WHEEL TIRE REPAIRS REPAIRS TIRE OUTSIDE-IN OR ON-THE-WHEEL disposal. mendations for installation manufacturers’ Material Safety Data Sheets and instructions. Follow repair materials manufacturers’ recom materials repair Follow Refer Refer to the information on the product or

(MSDS) and follow guidelines for handling and handling for guidelines follow and (MSDS) Repair procedures require the following: V. REPAIRING Medium Truck, Heavy Radial Truck, and Bus Tires discoloration of the inner liner inner the of discoloration soft spots or when rolling the tire the rolling when spotsor soft broken cords broken Soft spot(s) in the sidewall flex area flex sidewall the in spot(s) Soft Creasing, wrinkling, cracking or Protruding filaments indicating Any popping sound when feeling for for feeling when sound popping Any

Inner Liner Repair Bead Area Repair Spot Repair 6. (See images on the following page.) following the on images (See 5. 3. 4.

B. in the body plies should be rejected. should body plies the in casing manufacturerfor inner liner repair or improve appearance. A spot repair does does repair A spot appearance. improve or radial heavy truck, medium on damaged or with Tires repaired. be bead broken or exterior of a tire, generally to avoid moisture evidence of bead area separationor rusting spot repaired, but should be considered for for considered be should but repaired, spot sectionrepairing. specifications. truck or bus tires. In no case should a kinked kinked a should case no In tires. bus or truck not expose cord, tool damage or blisters blisters or damage tool cord, expose not may be repaired in tubeless tires. Consult penetration into the casing, limit cut growth cutgrowth limit the casing, into penetration unit. repair a reinforcing of use the require not exposed is chafer the where except repairs, C. MINOR RUBBER REPAIRS RUBBER MINOR Open Open inner liner splices, cracks which do with damage to the body cords cannot be be cannot body cords the to damage with Medium truck, heavy radial truck or bus tires only rubber to limited are repairs area Bead A. A spot repair is one that is performed to the the to performed is that one is repair A spot

should be performed in a full-service repair facility. repair a full-service in be performed should for a definition of “Full Service Repair Facility”. Repair Service “Full of a definition for See Appendix 1 - Common Retread and Repair Repair and Retread 1 - Common See Appendix Minor repairs are generally rubber only repairs, but repairs, only rubber generally are repairs Minor VI. Terminology - A Compendium of Industry Terms Terms Industry of - A Compendium Terminology 48 prior to prior to inner liner or bead area on tires tires on area bead or liner inner identifiedtubeless as underinflated oroverloaded underinflated to be defective and unrepairable and be defective to non-repairable bead area beyond repairable limits breaks any evidence of having been run run been having of evidence any Injuries to the body plies in the the in body plies the to Injuries the to damage Non-repairable Loose cords on the inside ply or or ply inside the on cords Loose cords body ply the to Injury impact or X-breaks breaks, Flex Previously installed repairs found

irregularities cords or steel produce shadows left by any sidewall sidewall any by left shadows produce and/or bulges) visible when using using when visible bulges) and/or an indirect light source which will Cuts, snags or chips exposing body exposing chips or snags Cuts, Distortions or undulations (ripples Repairing Medium Truck, Heavy Radial Truck, and Bus Tires Bus and Truck, Heavy Radial Truck, Medium Repairing g. c. e. d. h. f.

Zipper Indicators Damage 2. 1.

it is also recommended that some type of type some of that recommended also is it is found in the valve assembly or in the bead bead the in or assembly valve the in found is B. of weakness or non-repairable injury (e.g., (e.g., injury non-repairable or weakness of conditions, checkthe valve assembly and electrostatic,high etc.) pressure tester, be detection solution, where practical,detectionwhere solution, demounting and deflating the tire. If a leak a If tire. the deflating and demounting utilized for casing inspection. for casing utilized sidewall, particularly the upper sidewall. Steel Steel sidewall. particularly upper sidewall,the scrapped. and rejected be should since the tire will not hold air. hold not will tire the since ripples, bulges, porosity, softness, etc.)in the belted radial tires exhibiting such conditions nondestructive inspection equipment (e.g., ultrasonics, X-ray, shearography, holography, bead area for leaks using a water or leak leak or a water using leaks for area bead area, certain repairs may not be possible be possible not may certain repairs area, Indications of zipper damage include any signs any include damage zipper Indications of Furthermore, along with visual inspection, In In additionto checkingfor non-repairable REPAIRING Medium Truck, Heavy Radial Truck, and Bus Tires Trim Excess Rubber Excess Trim Inspection Pre-Cleaning

injury. of damage. If the damage extends to the the to extends damage the If damage. of to the body cables, treat as a spot repair. repair. a spot as treat bodycables, the to ultrasonics, electrostatic, high pressure body cables and there is no rust or damage damage or rust no is there and body cables 3. nondestructive inspection equipment inspection. casing for utilized be etc.) tester, also recommended that some type of type some of that recommended also SectionRepairs portion ofthis document Inspect the injury to determine the extent extent the determine to injury the Inspect the to refer damage, body cable is there If Remove all contaminants from around the In addition to visual inspection, it is is it inspection, visual to addition In (see sectionX). (see X-ray, shearography, holography, (e.g., 2. type truck tires, without repair. Some cord trimmingbe may necessary. Consult tire manufacturer for bead area repair specifications. repair area bead for manufacturer Minor chafer damage is allowed in some tube some in allowed is damage chafer Minor overloaded, and should be inspected accordingly. sealing capabilities require specialized repair should be contactedfor recommendations. It may techniques. The tire and/or sealant manufacturers sealant and/or tire The techniques. puncture sealant(s) may have been have may puncture damaged sealant(s) as a result of being run underinflated and/or 2.) Tires2.) that are manufactured with puncture 1.) 1.) Tires that contain any type of aftermarket NOTE: 49 - Stitch Repair Area Stitch near fire, flame flame fire, near solvents CAUTION WARNING Repairing Medium Truck, Heavy Radial Truck, and Bus Tires Bus and Truck, Heavy Radial Truck, Medium Repairing Fill Injury Probing and Foreign Material Removal Material Foreign and Probing use flammable flammable use

Steps for Minor Rubber Repairs Rubber Minor for Steps any foreign material. Use a probe to inspect the damage. Remove Remove damage. the inspect to a probe Use 1. REPAIR MATERIAL MANUFACTURERS MATERIAL REPAIR

the original contour of the bead. In addition, addition, In bead. the of contour original the bead repairs on a tubeless tire should restore restore should tire tubeless a on repairs bead and maintain its air retention capability. retention its air maintain and Bead Bead area repairs on all tiresshould restore D. perform a minor rubber repair. rubber perform a minor DO NOT MIX PRODUCTS DIFFERENT FROM The steps listed below are essential to to essential are below listed The steps BEAD AREA REPAIR AREA BEAD DO NOT DO disposal. mendations for installation and instructions. Safetymanufacturers’ SheetsData Material serious personalserious injury or death. or any other source of ignition. Explosiveforce and/or fire from ignition of solvents could cause could solvents of ignition from fire and/or Follow repair materials manufacturers’ recom materials repair Follow Refer Refer to the information on the product or (MSDS) and follow guidelines for handling and and handling for guidelines follow and (MSDS) REPAIRING Medium Truck, Heavy Radial Truck, and Bus Tires 3/8”

(NAIL HOLE REPAIR) HOLE (NAIL ARE NOT RECOMMENDED. NOT ARE SPECIFIC REPAIR PROCEDURES. REPAIR SPECIFIC and Bus Tire Puncture Repair Tire Bus Puncture and Medium Truck, Heavy Radial Truck, Truck, Heavy Radial Truck, Medium equipment and materials manufacturers’ recommendations. For chemically activated chemically For recommendations. repairs, allow sufficienttime forcuring as manufacturer. the by recommended ASSEMBLY FOR INTERNAL INSPECTION. FOR INTERNAL ASSEMBLY CONTACT TIRE MANUFACTURERS FOR MANUFACTURERS TIRE CONTACT

rubber stem Preparing the injured area Filling the injury with a suitable Reinforcing and sealing the repair area Removal of damaged material vulcanizing material or vulcanizing

NEVER PERFORM A TIRE REPAIR WITHOUT REPAIR A TIRE PERFORM NEVER

REMOVING THE TIRE FROM THE RIM/WHEEL THE RIM/WHEEL FROM THE TIRE REMOVING to the tread area only, and not exceed not and only, area tread the to radial radial truck, and bus tiresshould be limited PUNCTURE REPAIR REPAIR PUNCTURE Puncture repairs for medium truck, heavy A. • • • •

OUTSIDE-IN OR ON-THE-WHEEL TIRE REPAIRS REPAIRS TIRE OUTSIDE-IN OR ON-THE-WHEEL should should be based on or recommendations repair etc.). applications, service commercial technology, policy of the tiremanufacturer and/or typeof Not all tires can be repaired. Specific repair limits repair Specific repaired. be can tires all Not tireservice (e.g., service description, run-flat or leak detection solution,where practical. If a NOTE: the valve and outer surface for leaks using a water water a using leaks for surface outer and valve the leak is found in the valve assembly or in the bead bead the in or assembly valve the in found is leak the in found is leak no If air. hold not will tire the tire. the demount and deflate, totally injury, the area, a puncture repair may not be possible since since be possible not may repair puncture a area, Prior to demounting and deflating the tire,check theand deflating to Prior demounting Determine the extent and location of any injuries. Repair procedures require the following: valve assembly or bead area, proceed by marking marking by proceed area, bead or assembly valve VII. - 50 cement near fire, flame WARNING Repairing Medium Truck, Heavy Radial Truck, and Bus Tires Bus and Truck, Heavy Radial Truck, Medium Repairing Curing Cementing Cleaning Buffing use flammable

Filling

8. 6. climate conditions, extend the dryingconditions, extendtimethe climate 5. surfaces because the unfilteredair lines may contain contaminants such as oil and and oil as such contaminants contain may whichmoisture, can reduce adhesion. temperature, and pressure according to the streaking. Allow the cement to dry for the drythe to for cement the Allow streaking. material. prepared surface prepared or no with puddling humid and/or cold In time. recommended from the buffed area with a fine wire brush brush wire fine a with area buffed the from and vacuum to provide a clean, dry surface. ate ate buffing tool,while keeping the repair area as small as possible. as recommended by the manufacturer. the by recommended as Shape the repair with a low-speed (i.e., (i.e., a low-speed with repair the Shape Cure the repair for the specified time, time, specified the for repair the Cure Do not use compressed air to clean bonding bonding clean to air compressed use Do not Bufftheinjury to a achieve TRMG uniform BT1 or BT2 bufftexture for all(see repairs Buffing “BTS6 - Standard 01/02-23 RP Remove all damaged or loose material. Remove any rubber dust and contaminants Fill the injury with a suitable vulcanizing 4. 5,000 rpm bufferand maximum) appropri Apply the appropriate cement to the the to Apply cement appropriate the Textures for Tire Retreading and Repairing”). forTextures Tire Retreading and Repairing”). 7. ensure that the repair area is free of contaminants. of free is area repair the that ensure be necessary to repeat step 3, pre-cleaning, to to pre-cleaning, 3, step repeat be necessary to DO NOT DO serious personalserious injury or death. or or any other source of ignition. Explosive force and/or and/or fire from ignition ofcement could cause REPAIRING Medium Truck, Heavy Radial Truck, and Bus Tires - near fire, flame flame fire, near

solvents Drill Injury - Inside Tire CAUTION WARNING Buff Injury - Outside of Tire use flammable flammable use Steps for Steps Puncture Repair REPAIR MATERIAL MANUFACTURERS MATERIAL REPAIR

B. on the following pages.) puncture in medium truck, heavy radial truck, and bus tires. (See repair images below and and below and images bus (See tires. repair DO NOT MIX PRODUCTS DIFFERENT FROM The steps listed below are essential to repair a repair to essential are below listed steps The DO NOT DO disposal. mendations for installation manufacturers’ Material Safety Data Sheets and instructions. serious personalserious injury or death. or any other source of ignition. Explosiveforce and/or fire from ignition of solvents could cause could solvents of ignition from fire and/or Follow repair materials manufacturers’ recom materials repair Follow Refer to the information on the product or (MSDS) and follow guidelines for handling and handling for guidelines follow and (MSDS) - 51 Mark Injury - Inside Tire Remove Injury - Outside of Tire Remove FIGURE 1 FIGURE Repairing Medium Truck, Heavy Radial Truck, and Bus Tires Bus and Truck, Heavy Radial Truck, Medium Repairing injuries, and those in the shoulder and sidewall instructions in sectionin Repairs. X,Section instructions dices located at the end of this document.) this of end the at located dices repair facility. (Refer to Tables I, II-A and Appen and II-A I, Tables to (Refer facility. repair the graphic. If the injury damage exceeds exceeds damage injury the If graphic. the injury the then limits, repair puncture the radial truck/bus and tire, indicates that belt tread the to limited are repairs puncture in depicted generally as only area package Follow must a be sectionconsidered repair. areas, should only be repaired in a full-service in be repaired only should areas, Figure 1 represents a medium truck/heavy truck/heavy medium a represents 1 Figure (10.0 mm) diameter mm) after preparation.(10.0 Larger PUNCTURE REPAIR Drill Injury - Outside of Tire Spread Beads for Inspection Beads for Spread Mark and Remove the Injury Mark and Remove REPAIRING Medium Truck, Heavy Radial Truck, and Bus Tires Texturize Repair Area Repair Texturize Trace Around Repair Unit Template Repair Around Trace Preparation of the Injury of the Preparation Inspection

injury. determine the angle of penetration. penetration. of angle the determine that has penetrated the tire. the penetrated has that Inspect andremove anyforeign material Remove all contaminants from around the Probe the injury with a tire probe to to probe tire a with injury the Probe 2. 1. Remove Injury Remove Measure the Injury Measure overloaded, and should be inspected accordingly. ensure that the repair area is free of contaminants. of free is area repair the that ensure sealing capabilities require specializedrepair should be contactedfor recommendations. It may techniques. The tire and/or sealant manufacturers sealant and/or tire The techniques. to pre-cleaning, 2, step repeat be necessary to puncture sealant(s) may have been have may puncture damaged sealant(s) as a result of being run underinflated and/or 2.) Tires2.) that are manufactured with puncture 1.) 1.) Tires that contain any type of aftermarket PUNCTURE REPAIR PUNCTURE REPAIR NOTE: Measure for Repair Unit and Buff - Inside Tire Repair for Measure REPAIRING Medium Truck, Heavy Radial Truck, and Bus Tires Cement Repair Area Repair Cement WARNING use forced air or an outside heat or outside an use air heat forced Fill the Injury the Fill Cementing

8. 9. surfaces because the unfilteredair lines may contain contaminants such as oil and and oil as such contaminants contain may whichmoisture, can reduce adhesion. surface and, if required, to the back of the the of back the to required, if surface and, the recommended time. While drying, the the injury with the appropriate material. repair unit. Allow the cement to dry to for cement the Allow unit. repair tire. the of bottom the at positioned not material or material a rubber vulcanizing stem, fill Do not use compressed air to clean bonding bonding clean to air compressed use Do not If using uncured/suitable vulcanizing tire should be rotated so that the injury is injury the that so rotated be should tire Apply appropriate cement to the buffed cement nearflammable DO NOT use fire, flame serious personalserious injury or death. or any other source of ignition. Explosive force force Explosive ignition. of source other any or and/or fire from ignition of cement could cause cause could cement of ignition from fire and/or DO NOT DO NOT source to accelerate drying time. Refer to repair materials manufacturer recommendations. 53 Vacuum Buffing Dust Buffing Vacuum Repairing Medium Truck, Heavy Radial Truck, and Bus Tires Bus and Truck, Heavy Radial Truck, Medium Repairing Inner Liner Buffing Repair Unit Selection Unit Repair

Cleaning

greater than 25 degrees, depending on on depending degrees, 25 than greater 6. ensure that crayon marks are not removed removed not are marks crayon that ensure 5. section X.B.). repair manufacturer, use atwo-piece manufacturer, repair repair unit system. the injury and outline an area about 1/2” 1/2” about area an outline and injury the liner splits. If present, this is no longer longer no is this present, If splits. liner the the outline, buffwithin the marked area speed a low using evenly and thoroughly based on repair material manufacturer recommendations. Centerthe unit over from the buffed area with a fine wire brush brush wire fine a with area buffed the from not not to expose or damage the tire casing cords. Bufftosurface; body avelvet (ply) and vacuum to provide a clean, dry surface. a puncture repair. Refer to the Section Section the to Refer repair. puncture a Select the appropriate repair unit when when buffing.For injuries with an angle Repairs. Inspect prepared injury for inner (see document portion this of Repair Remove any rubber dust and contaminants (13.0 mm) larger than the repair unit, to to unit, repair the than larger mm) (13.0 (i.e., 5,000(i.e., rpm buffermaximum) with a finewire brush or Take care gritted rasp. 7. To To prevent contamination and preserve TRMG BT1 or BT2 or texture. BT1 TRMG PUNCTURE REPAIR cont. PUNCTURE REPAIR Repair Area After Filling and Buffing and Filling After Area Repair Clean Repair Area and Apply Cement - Inside Tire and Apply Cement Area Clean Repair REPAIRING Medium Truck, Heavy Radial Truck, and Bus Tires

Remove Film from Repair Unit Repair Film from Remove Inspect Areas Repair Curing

continue repair if the buffed area exposes installation. Cutthe fill material flushwith a proper not is only (stem) a plug or only chemically chemically activatedrepairs, allow sufficient outwards to the edges. Check for proper proper for Check edges. the to outwards unit, look for signs of tire casing body cords. body casing tire of signs for look unit, spotter, section mold or curing chamber, follow chamber, curing or mold section spotter, time for curing as recommended by the stretch or pull the stem while cutting. stem is Ifnot flushthewith tread after cutting, must be cured completely. When using a using When completely. cured be must the manufacturers’ recommendations. Also pressure and temperature, time, specified the manufacturers’ recommendations. For manufacturer. puncture repair. (See section XI, Repair Repair XI, section (See repair. puncture the outer tread surface making sure not to to not sure surface making tread outer the tread. with level is it until buff lightly follow the manufacturers’for recommendations repair the Cure time. cure calculating for and the edge of the repair unit. A patch A patch unit. repair the of edge the and according to the equipment and materials If the buffed area extends beyond the repair repair the beyond extends area buffed the If Finishing.) vulcanizing material or vulcanizing rubber stem, Apply repair sealant to the over-buffed area area over-buffed the to sealant repair Apply 13. 12. The repair unit and uncured/suitable The unit and uncured/suitable repair DO NOT body cords. 54 DO Stitch Repair Unit Stitch cont. excess material inside the tire, and cement the injury channel, insert designed for Without injury. that size stretching the stem, cut/trim the to accommodate the appropriate size buff the stem flush with the inner liner inner the with flush stem the buff repair unit. stem), cement the injury channel and channel injury the cement stem), the stem from the inside of the tire, of the stem from the tire, the inside the against snug is unit repair the the innerliner. prepared and cemented surface cemented and ofprepared a suitable vulcanizing rubber stem and and pull through untilthe base of (i.e., (i.e., separate repair unit and filler fill the injury from the inside with When using a two-piece unit repair When using a one-piece unit, repair

Repairing Medium Truck, Heavy Radial Truck, and Bus Tires Bus and Truck, Heavy Radial Truck, Medium Repairing Stitching Repair Unit Repair Installation b. a.

on the repair unit. Avoid trapping air and/or and/or air trapping Avoid unit. repair the on beads beads of the tireare in arelaxed position. installed. is it as unit the of bridging possible Repair units are to be installed while the the while installed be to are units Repair Align the repair unit according to the markings markings the to according unit repair the Align cement the stem. cement Instead, the injury unit unit starting from the center, and work For For all methods, stitch the entire repair 11. 10. Install Repair Unit Repair Install channel. NOT Remember, for both types of repair units, units, types repair of both for Remember, PUNCTURE REPAIR PUNCTURE REPAIR Install Repair Unit - Inside Tire Unit Repair Install REPAIRING Medium Truck, Heavy Radial Truck, and Bus Tires or longer repair unit (if using the RSR the using (if unit repair longer or type of injury requires the use of a #22 a #22 of use the requires type injury of required for a maximum 5/16” (8.0required for a maximum 5/16” injurymm) in the shoulder area. This recommendations). Otherwise referto manufacturers’ recommendations. A longer repair unit than a #20 is a #20 than unit repair A longer guidelines of the template. indicate that a repair unit is installed. of the tire nearest the RSR injury to injury the RSR nearest tire the of any FLEX ZONE. FLEX any Keep prepared damage within the the within damage prepared Keep Use a BLUE TRIANGLE on the sidewall sidewall the on TRIANGLE a BLUE Use Avoid ending repair unit placement in

Benefit of Offsetting a Repair Unit of Repair Benefit a Offsetting (non-centered) •

B. Moves edge of repair unit away from the FLEX the from away unit repair of edge Moves 3. ZONE. 2. 1. SUMMARY REINFORCED- SHOULDER REPAIRS - 55 WHY REINFORCED Repairing Medium Truck, Heavy Radial Truck, and Bus Tires Bus and Truck, Heavy Radial Truck, Medium Repairing SHOULDER REPAIR (RSR)? SHOULDER REPAIR Reinforced Shoulder Repair (RSR) Reinforced Shoulder (RSR) Repair REINFORCED SHOULDER REPAIR REINFORCED SHOULDER REPAIR Unit Placement Unit

(i.e., maximum 8.0 mm) in or near the shoulder. closer than 3/8” (10.0 mm) to the bead toe. toe. bead the to mm) (10.0 3/8” than closer require one anchor point in the crown area area crown the in point anchor one require procedure will require an up-sizing of the repair unit in an effort repair proper to accomplish to as so length, gain additional position). non-flex to non-flex (i.e., placement and and another anchor point out of the FLEX Shoulder and sidewall injuries generally See Figure 2 and Appendix 6. Appendix 2 and See Figure A. ZONE, ZONE, near the bead area of the tire. This Therepair unit should not be installed any Improves repair reliability for small punctures/injuries Improves repair reliability for small punctures/injuries injuries are directly adjacent to the sidewall FLEX to the sidewall are directly adjacent injuries of the tire, the additional stress on the repair unit repair the on stress theadditional tire, of the center to accommodate full injury security.When end of ends the repair in body, a high-flex portion repair results in a full service repair facility. the the selection methods and placement of the so that the unit placement can be anchored in in be anchored can placement unit the so that repair repair unit is vital to attaining permanentrepair results. These guidelines are writtento explain length length a repair unit can be shiftedover an injury non-flex zones of the tire casing. Because shoulder specificto injuries in the shoulder area of tires the anchor portion of the repair unit, 25% on each on 25% unit, repair the of portion anchor the because of incorrect repair unit selection and place and selection unit repair incorrect of because cord unit’s repair the in result can body structure lifting. edge and/or breakout ment. Repair unit construction design normally appropriate repair unit to achieve permanent permanent achieve to unit repair appropriate allows for allows 50% of the unit repair to be off- shifted Repair unit manufacturers typically produce VIII. ZONE of tires, placement and size selection of the The industry has experienced repair unit issues issues unit repair experienced has The industry “templates” that indicate the injury width and REPAIRING Medium Truck, Heavy Radial Truck, and Bus Tires - (located at the end of end the at (located

CAUTION in excess of puncture (i.e., nail hole) hole) nail (i.e., puncture of excess in on the materials and equipment being being equipment and materials the on used. should be made when all of the injury injury the of all when be made should repairing tires. The method is dependent this document) show the maximum maximum the show document) this tires. truck radial repairability and repair unit selection removed. been has bus tires with damage to body ply cords repair limits, require a section repair. allowable limits for medium and heavy Finalmeasurements to determine Medium truck, heavy radial truck, and and truck, radial heavy truck, Medium There There are several methods for section Tables I and II-ATables

Steps forSteps SectionRepairs SectionRepair Limits 3. 2. 1. REPAIR MATERIAL MANUFACTURERS MATERIAL REPAIR

B. on the following pages.) SECTION REPAIRS SECTION a sectionin repair aimages tire. (See repair A. DO NOT MIX PRODUCTS DIFFERENT FROM The steps listed below are essential to making making to essential are below listed steps The disposal. mendations for installation manufacturers’ Material Safety Data Sheets and instructions. Follow repair materials manufacturers’ recom materials repair Follow Refer Refer to the information on the product or (MSDS) and follow guidelines for handling and handling for guidelines follow and (MSDS)

repair limits. These limits should be based on on based be should limits These limits. repair recommendations ofthe tiremanufacturer, repair service. type tire and of manufacturer, materials and repair material manufacturerspecificregardingmaterial repair and Determine Determine the extent and locationof any injuries. Repair shops should consult the tiremanufacturer X. 56 - flame near fire, solvents CAUTION WARNING Repairing Medium Truck, Heavy Radial Truck, and Bus Tires Bus and Truck, Heavy Radial Truck, Medium Repairing New RSR designation New retreaders to specifications Fleet use flammable

specification changes: specification service providers. associations to revise and update repair repair update and revise to associations Educate your fleet customers and and customers fleet your Educate TRMG is working with other industry industry other with working is TRMG • • Reinforcement Repair Limits Repair Reinforcement Steps for Repairs Steps Reinforcement REPAIR MATERIAL MANUFACTURERS MATERIAL REPAIR

B. document (See section X.B., Steps for Section repair; a section repair is required. is a sectionrepair repair; REINFORCEMENT REPAIRS Repairs.) Refer Refer to the SectionRepairs portion of this Medium truck, heavy radial truck, and bus bus and truck, radial heavy truck, Medium 5. A. tires cannot be repaired with a reinforcement reinforcement a with repaired be cannot tires 4. DO NOT MIX PRODUCTS DIFFERENT FROM

DO NOT DO disposal. mendations for installation manufacturers’ Material Safety Data Sheets and instructions. serious personalserious injury or death. or any other source of ignition. Explosiveforce and/or fireand/or from ignition of solventscould cause Follow repair materials manufacturers’ recom materials repair Follow Refer Refer to the information on the product or (MSDS) and follow guidelines for handling and handling for guidelines follow and (MSDS) IX. repair limits. These limits should be based on based be should limits These limits. repair recommendationsof the tire manufacturer, repair service. type tire and of manufacturer materials and repair material manufacturer regarding specific Determine Determine the extent and locationof any injuries. Repair shops should consult the tiremanufacturer REPAIRING Medium Truck, Heavy Radial Truck, and Bus Tires Remove Injury Remove Mark Injury - Outside Tire Injured Area Ready for Cement for Ready Area Injured Inspection Pre-Cleaning

injury. determine repairability and the extent of of extent the and repairability determine damages. 3. Inspect, mark, and measure all injuries to to injuries all measure and mark, Inspect, Remove all contaminants from around the 2. overloaded, and should be inspected accordingly. puncture sealant(s) may have been have may puncture damaged sealant(s) as a result of being run underinflated and/or 1.) 1.) Tires that contain any type of aftermarket NOTE: 57 Texturize Injury Texturize Mark Injury - Inside Tire Drill Injury - Outside Tire near fire, flame flame fire, near solvents WARNING Repairing Medium Truck, Heavy Radial Truck, and Bus Tires Bus and Truck, Heavy Radial Truck, Medium Repairing Probing and Foreign Material Removal Material Foreign and Probing use flammable flammable use

foreign material that has penetrated the tire. Remove Injury Remove Use a probe to inspect and remove any any remove and inspect to probe a Use 1. SECTION REPAIR SECTION Drill Injury - Inside Tire DO NOT DO serious personalserious injury or death. or any other source of ignition. Explosiveforce and/or fire from ignition of solvents could cause could solvents of ignition from fire and/or Spread Beads for Inspection Beads for Spread Mark and Remove Injury Mark and Remove REPAIRING Medium Truck, Heavy Radial Truck, and Bus Tires Texturize Repair Texturize Trace Around Repair Unit Repair Around Trace Apply Cement to Repair Area Repair to Apply Cement Repair Unit Selection Unit Repair

cables believed to be damaged (i.e., just just (i.e., be damaged to believed cables solid to back trimmed be must cables on the construction of the tire and the size 5. damage removal to ensure that no cuts or cuts or no that ensure to removal damage untilthey are visible). All damaged steel tire. the in remain separations to achieve a uniform TRMG BT2 or BT3 BT3 BT2 or TRMG uniform a achieve to after area repair the probe Always texture. rubber and very lightly expose only the the only expose very lightly and rubber 20,000a use steel, trimming For rubber. rpm bufferminimum andair/electric the 5,000maximum) rpm (i.e., low-speed tool texture buffing appropriate and buffer appropriate grinding tool. Buff with a Select the appropriate repair unit based based unit repair appropriate Select the 58 Buff Repair Area Buff Vacuum Buffing Dust Buffing Vacuum Measure for Repair Unit Repair for Measure Repairing Medium Truck, Heavy Radial Truck, and Bus Tires Bus and Truck, Heavy Radial Truck, Medium Repairing Skiving

texture tool, remove all damaged rubber rubber damaged all remove tool, texture (i.e.,5,000 a low-speed on tool texture maximum) buffer and appropriate buffing buffing appropriate and buffer maximum) rpm maximum) to buff away remaining above the steel cables, keeping the injury injury the keeping cables, steel the above as small as possible. Use an appropriate 4. Using a low-speed (i.e., 5,000 rpm 5,000 rpm (i.e., a low-speed Using Remove Injury Remove ensure that the repair area is free of contaminants. of free is area repair the that ensure sealing capabilities require specialized repair should be contacted for recommendations. It may techniques.The tire and/or sealant manufacturers to pre-cleaning, 3, step repeat to necessary be SECTION REPAIR cont. REPAIR SECTION 2.) Tires2.) thatare manufactured with puncture Area Marked for Repair Unit Repair for Marked Area Area After Buffing and Texturizing Buffing and After Area Injury Preparation and Repair Unit Selection - Inside Tire - Inside Selection Unit Repair and Preparation Injury REPAIRING Medium Truck, Heavy Radial Truck, and Bus Tires - installation. Inspect repair area. casing bodycasing cords. cemented surface of the inner liner. over-buffedarea and the edge of unit is snug against the prepared and prepared the against snug is unit the repair unit, look for signs of tire tire of signs for look unit, repair the sectionrepair unit, insert the stem to the edges. Check for proper proper for Check edges. the to through through untilthe base of the repair the repair unit. from the center, and move out out move and center, the from from from the inside of the tireand pull facturer, apply repair sealant to the the to sealant repair apply facturer, Stitch the entire repair unit starting unit repair entire the Stitch If If the buffedarea extends beyond If recommended manu by repair When using a one-piece chemical

c. Repair Unit Repair Installation Fill the Injury the Fill Cementing b. a.

use forced air or outside heat source to to source heat outside or air forced use 8. cement to the back of the repair unit if if unit repair the of back the to cement conditions,climate extend dryingthe time 9. evenly to all surfaces with no puddling or surface depending on the repair method method repair the on depending surface dry the to for cement the Allow streaking. being used. Also apply the appropriate be The should applied cement required. recommendedtime. In cold and/or humid as recommended by the manufacturer. manufacturer. the by recommended as Apply the appropriate cement on the buffed the on cement appropriate the Apply on the repair unit. repair the on DO NOT continueDO NOT the repair ifthe buffed stem. beads beads of the tirein the relaxed position. area exposes radial ply cords. cords. ply radial exposes area Repair units are to be installed with the the with installed be to are units Repair Fill the injury with an uncured/suitable vulcanizing materialor vulcanizing rubber Align the repair unit according to markings markings to according unit repair the Align 10. DO NOT DO accelerate dryingaccelerate time. 59 near fire, flame WARNING Repairing Medium Truck, Heavy Radial Truck, and Bus Tires Bus and Truck, Heavy Radial Truck, Medium Repairing Inner Liner Buffing cement flammable use

Cleaning

6. injury from the inside with a suitable a suitable with inside the from injury of the damage to the body cords or cables. cables. or body cords the to damage the of bonding bonding surfaces because the unfiltered speed speed (i.e., 5,000 rpm maximum) buffer the entire injury has been removed. Refer Refer removed. been has injury entire the I, II-Ato Tables and related diagrams for stem. Without stretching the stem, trim unit. texture. The buffed area should be slightly slightly be should area buffed The texture. materials manufacturers’ charts for proper selection. unit repair from the buffed area with a fine wire brush brush wire fine a with area buffed the from the excess material inside the tire, and larger than the repair unit. buff the stem flush with the inner liner to liner inner the with buff theflush stem and vacuum to provide a clean, dry surface. dry surface. a clean, provide to vacuum and air lines may contain contaminants such as oil and moisture, which can reduce adhesion. and and appropriate buffing texture tool to buffed BT2 or BT1 TRMG uniform a achieve at the end of this document), and to repair repair to and document), this of end the at accommodate the appropriate repair size Do not use compressed air to clean clean to air compressed use Do not Cement Cement the injury channel and fill the Remove any rubber dust and contaminants Buff the area for the repair unit with a low low a with unit repair the for area the Buff Final measurements should be made when when made be should measurements Final Maximum Injury Limits (see Tables section vulcanizing material or vulcanizing rubber 7. DO NOT DO serious personalserious injury or death. or any other source of ignition. Explosive force force Explosive ignition. of source other any or and/or fire from ignition of cement could cause cause could cement of ignition from fire and/or installed before buffing. before installed rubber rubber stem is used to fillan it injury, must be If a suitable vulcanizing material or vulcanizing vulcanizing or material vulcanizing suitable a If NOTE: REPAIRING Medium Truck, Heavy Radial Truck, and Bus Tires Stitch Repair Stitch Remove Film from Repair Unit Repair Film from Remove Inspect Areas Repair

General Repair Finishing General Repair

sufficient time for curing as recommended recommended as curing for time sufficient cords. body casing tire of signs for look unit, temperature, and pressure. For chemically chemically For pressure. and temperature, by the manufacturer. recommendations. Alsofollow the repair material and equipment manufacturers’ recommendations for calculating cure activated repair unit application, allow If the buffed area extends beyond the repair repair the beyond extends area buffed the If time. Cure the repair for the specified time, time, specified the for repair the Cure time. 12. should be placed on or next to the repair repair next or on the to be placed should performance and appearance of the repaired REPAIR FINISHING REPAIR Finishing is necessary to ensure satisfactory dating, and codes internal other or Code Plant A. tire. Repair identification, typically the DOT-R

XI. 60 Fill Repair Area Fill Repair Stitch Repair Unit Stitch FIGURE 3 Repairing Medium Truck, Heavy Radial Truck, and Bus Tires Bus and Truck, Heavy Radial Truck, Medium Repairing Curing

chamber, follow the manufacturers’chamber, using using a spotter, section mold curing or stem, must be cured completely. When When completely. be cured must stem, vulcanizing material or vulcanizing rubber 11. The repair unit and uncured/suitable The unit and uncured/suitable repair Install Repair Unit Repair Install Cement Repair Area Repair Cement inner liner wheel to buff for the blue triangle. triangle. blue the for buff to wheel liner inner recommended to use a blue triangle to identify the area asa section repair, as seen in Figure 3. Use the When repairing the shoulder or sidewall area, it is it area, sidewall or shoulder the repairing When SECTION REPAIR cont. REPAIR SECTION NOTE: Repair Unit Installation - Inside Tire Installation Unit Repair Fill InjuryOutside Tire - REPAIRING Medium Truck, Heavy Radial Truck, and Bus Tires FIGURE 4 uninflated or3/8” (10.0 mm) in

Sidewall InspectionSidewall inflated. The tire should be inspected Outside Inspection returned to service for a minimum of of a minimum servicefor to returned reached ambient air temperature. previously detected. Follow the OSHA followed whenfollowed the tire isand mounted at at this time for any anomalies not and Single-Piece C.F.R. Rim Wheels (29 Section repaired tires should not be Standards for Servicing Multi-piece § 1910.177). Approved procedures should be should procedures Approved 24 24 hours aftercuring, when they have

cured, trimmed, and has all the required seen in Figure 4. to ensure that it has been properly molded, molded, properly been has it that ensure to truck, heavy radial or bus truck tire may height when inflated to the recommendedthe to inflated when height pressure. the near triangle a blue placing by noted as tire, the of sidewall lower the on repair labeling. 3. 2/32” exceed not should bulge The bulge. (1.5 mm) 5. 2. 4. The The outside of the tire beshould checked The sidewall repaired area in a medium The The presence of a sectionrepair may be 61 Repairing Medium Truck, Heavy Radial Truck, and Bus Tires Bus and Truck, Heavy Radial Truck, Medium Repairing Inside InspectionInside Buffing Tread Design Tread

installed and bonded, and for any internal internal any for and bonded, and installed been have may that or conditions injuries contour contour and appearance of the tire. The Steps for Repair Finishing forSteps Repair the precured stem repair to the original may material repair rubber the surfaceof surrounding surface. (See Section XII.B., toensure that all repairs are properly phase. inspection initial the during missed not extend over 2/32” (1.5 mm) above the the above mm) (1.5 2/32” over extend not General Inspection Repair Criteria for InspectionRepair Criteria for Repair Inspection.) Repair for Criteria Restore tread design in the crown area. crown the in design tread Restore Buff the cured rubber filler material or trim trim or material filler rubber cured the Buff 2. 1. 1. The The inside of the tireshould be checked

inspection of repaired a tire. During the inspection process, the same stepsused in B. B. complete a repair. complete unit. The presence of a section repair may may repair section a of presence The unit. used to cure the repair, conduct the inspection used to the cure repair, seen seen in 3. Figure Section(See Criteria XII.B., the Final Repair Inspection. Repair Final the be noted by placing a blue triangle near the the near triangle a blue placing by be noted repair on the lower sidewall of the tire, as recommended) at the work surface. If heat is heat If surface. work the at recommended) mounted on a spreader under adequate lighting for Repair Inspection.) Repair for FINAL REPAIR INSPECTION REPAIR FINAL Conduct a finalexamination ofthe tire while while the repair is still warm. still is repair the while Initial TireInspection should be followed in (i.e., 200 fc / 2153 lx minimum, 300 fc / 3229 lx 300 / 3229 fc minimum, lx / 2153 200 fc (i.e., A. The steps listed below are essential for proper proper for essential are below listed steps The The steps listed below are essential to to essential are below listed The steps

XII. TABLES TABLE I NON-REPAIRABLE BEAD AREA FOR BODY PLY DAMAGE*

To determine the non-repairable bead area, measure with a narrow flexible rule following the inside contour of the liner from the bead toe.

RADIAL TIRE CROSS SECTION DIMENSION OF TIRE AREA*

All Radial Passenger Car 1-1/2 in. (40 mm)

Light and Medium Truck - Tube-type up to 3 in. (75 mm) 3-1/2 in. (90 mm) 7.50 (195mm) 8.25 (205mm) and above

Light and Medium Truck - Tubeless up to 8.5 3 in. (75 mm) 3-1/2 in. (90 mm) (215mm) 9 (225mm) and above

*Rubber spot repair only in this area. Repair to body ply and/or bead wire in this area is not permissible, and rust or damage to the bead bundle is non-repairable.

TABLE II MAXIMUM SECTION REPAIR LIMITS FOR RADIAL PASSENGER CAR AND LIGHT TRUCK RADIAL FABRIC BODY PLY TIRES

Repair material manufacturers and new tire manufacturers recommendations differ. Specific limits should be based on recommendations of tire manufacturers, repair material manufacturer, and type of tire service. Consult tire manufacturer and repair material manufacturer for acceptability of any repair beyond a tread area nail hole as previously covered in this document.

63 TABLE II-A MAXIMUM SECTION REPAIR LIMITS FOR RADIAL TRUCK TIRES See Appendix 3 - Measuring Injuries in Radial Tires

RADIAL LIGHT TRUCK AND TRUCK TIRE REPAIR CHART Tire Type and Size Sidewall Width Sidewall Length Shoulder Diameter Crown Diameter Light Truck Load Range D and Above 6.50 – 12.50 3/8” (10mm) 3-3/4” (95mm) 1/2” (15mm) 1” (25mm) 215/85 – 255/85 1/2” (15mm) 3-3/4” (95mm) 215/75 – 265/75 3/4” (20mm) 2-1/2” (60mm) 1” (25mm) 2” (50mm)

Medium Truck

7.50 – 10.00 3/8” (10mm) 3-3/4” (95mm) 1/2” (15mm) 1” (25mm) 8 – 11 1/2” (15mm) 3-3/4” (95mm) 215/75 – 285/75 3/4” (20mm) 2-1/2” (60mm) 1” (25mm) 2” (50mm) 4” (100mm)

Heavy Truck 11.00 – 16.00 3/8” (10mm) 5-1/8” (130mm) 1” (25mm) 1-1/2” (40mm) 12 – 18 1/2” (15mm) 5-1/8” (130mm) 295/80 – 445/65 3/4” (20mm) 5” (125mm) 435/50 – 495/50 1” (25mm) 4” (100mm) 1-1/2” (40mm) 3” (75mm)

Wider sidewall repairs should be shorter in length. Any “in-service” repair-related sidewall bulge should be no greater than 3/8” (10 mm) above the surrounding surface of an inflated tire.

NOTE: Dimensions shown are for general guidance. Repair material manufacturers’ and new tire manufacturers’ recommendations may differ. Specific limits should be based on recommendations of tire manufacturer, repair material manufacturer, and type of tire service. Consult tire manufacturer and repair material manufacturer for tire size not covered. See Appendix 4, Repairable Areas in Radial Tires, for additional reference information.

64 APPENDICES Appendix 1

Common Retread and Repair Terminology - A Compendium of Industry Terms

ABRASION - The rapid wearing away of a tire in-service AWL - A pointed, round or flat tool used to probe by scraping or rubbing. punctures and/or other injuries. ABRASION, SIDEWALL - An injury to the tire caused AWLING - See VENTING. by scraping or rubbing it against another material or structure. BACKING - A removable protective material used on the application side of retread rubber and repair materials to ACCELERATOR - A chemical that affects the rate of preserve cleanliness and tackiness. vulcanization of rubber compounds. BALANCING - A process to correct for heavy or light areas ACTIVATOR - Chemicals added to rubber compounds of weight of a tire and/or tire/rim/wheel and wheel end to activate accelerators to speed up the vulcanization assembly. process. BALLAST - The addition of fluids inside a tire or external ADHESION - Bond between two cured surfaces. weights applied to a vehicle to increase the load of drive axles on vehicles. ADHESIVE - See CEMENT. BANBURY - An enclosed machine for mixing rubber and AFTER CURE - The process of cool down after the rubber compounds. product is removed from direct heat vulcanization. BAND LUGGING - A method of retreading earthmover AGING - Evolution or change of physical and chemical tires using hand built-up extruded lugs and autoclave cure. properties of rubber by oxidation, heat, operating stresses or moisture over a period of time. BAR - Measure of pressure in international units. 1 bar = 0.9869 atm = 14.50 psi = 100 kPa. See USEFUL AIR INJECTION - An inspection method using a high- CONVERSION FORMULAS on page following industry pressure air probe to detect separation. terms. AIR PRESSURE - Force exerted by air within a tire, BASE WIDTH - A measurement of the width of the tread expressed in pounds per square inch (psi), kilopascals rubber which joins to the buffed surface of the tire. (kPa) or bars. BEAD - The anchoring part of the tire which is shaped AIRBAG - An inflated flexible bag used to impart positive to fit the rim/wheel; made of high tensile steel wires pressure on the article being vulcanized. wrapped and reinforced by the plies. ALIGNMENT - The requirement to have all wheels on BEAD AREA (Non-Repairable) - a specific measured a vehicle running in the same direction. This is accom- dimension, based on a tire size, where an injury through plished by adjusting various parts of the vehicle’s the body ply material should not be repaired. These suspension system to ensure proper handling stability dimensions are generally found on repair material manu- and to minimize abnormal treadwear. facturers wall charts. AMBIENT TEMPERATURE - Temperature (°F or °C) of BEAD AREA COVERING - The outermost material protect- immediate surroundings, usually room temperature. ing the bead area while providing a tapered seat to fit the rim configuration. ANTIOXIDANT - A chemical used to retard deterioration due to heat, light, oxygen or combinations thereof. BEAD BUNDLE (Non-Repairable) - Central core of the bead. A high strength, high tensile, brass plated carbon ARAMID - A class of heat resistant, high-strength steel wire wound from a continuous strand into a high synthetic fiber-type material used to form a ply cord. strength unit. This major structural unit provides the anchor of the tire to the rim. ARC - See TREAD RADIUS. BEAD CENTERING PLATE - An alignment device used to ASPECT RATIO - Ratio of the section height to the section reduce tire diameter and center the casing in the retread width of a tire. matrix. ASYMMETRIC - A tread pattern or crown plies that differ BEAD FACE/LEDGE/SOLE - The flat portion of the bead in aspect or construction between the outer and inner between the heel and toe that contacts the rim/wheel. shoulder areas of a tire. Such tires are directional. BEAD FILLER - Sometimes called an “apex”, it is designed AUTOCLAVE - A heated pressurized vessel used for to provide stiffness, stability, and durability in the bead vulcanizing rubber products. area.

66 Common Retread and Repair Terminology - A Compendium of Industry Terms

BEAD HEEL - The rounded portion of the bead that BLADDER CURE - A method of shaping and curing a tire contacts the rim/wheel between the bead seat and using an expandable cylindrical rubber assembly. flange. BLOW - A porous condition caused by a loss of pressure BEAD PLATE- Ring-shaped plates in molds which may be or undercure. See POROSITY. adjusted to alter the cross section of tires. BLOW OUT - Rapid loss of air due to rupture. BEAD REINFORCE - May be steel, fabric or a combination of reinforcing materials to give the bead stability and BLOW POINT - The curing time which is just less than that strength. See CHAFER. needed to develop a non-porous cure.

BEAD SEALING AREA - The face/ledge/sole and heel of BLUE TRIANGLE - A bulge due to a section repair is the bead that contacts the rim. With tubeless tires, the allowed not to exceed 3/8” (10 mm) in height. This bulge bead seals to the rim and rim flange to retain air. may sometimes be identified by a blue triangular label in BEAD SEAT - The flat portion of the rim/wheel on which the immediate vicinity. the bead face/ledge/sole rests. BODY - Tire structure excluding tread and sidewall rubber. BEAD SEPARATION - Separation between components in the bead area. BODY PLY(IES) - Layers of rubber-coated parallel cords extending from bead to bead that encase both bead BEAD-TO-BEAD MEASUREMENT - The distance from the bundles and provide strength to withstand inflation heel of one bead, straight up at 90°, over the crown and pressures and tire dimensions. down the other side to a position on the heel of the other bead directly opposite the starting point. Measurement BODY PLY INSERT - An additional layer of rubber on top of is used before retreading to predetermine the correct the body ply to add to body ply durability. buffing dimensions, rubber size, and curing matrix to be used in the processing. BONDING - The joining of two materials by use of adhesives or vulcanization. BEAD-TO-BEAD RETREADING - A retreading process which includes veneering of the sidewall from the BRAND NUMBER - A number branded into one or both shoulder to the bead. sidewalls of a tire for identification purposes.

BEAD TOE - The pointed part of the bead, opposite the BREAK - A surface opening and/or damage extending into heel, which faces the inside of the tire. or through the cord.

BEAD WIDTH - Measurement commonly used for the BREAKER (BELT OR STRIP) - In bias/diagonal tires, a proper fit (bead spread) during buffing process. band or strip of rubber-coated bias-cut tire cord placed BEAD WIRE - See BEAD BUNDLE. circumferentially around the tire between the last ply of casing fabric and tread. Sometimes called the impact or BELT - A reinforced cord layer located circumferentially shock ply. around the tire and under the tread. BUCKLE - Tire distortion caused by improper molding, BELT EDGE FILLER - A special rubber covering over steel evidenced by wrinkling on the inside of the casing. belt edges to resist belt edge fatigue. BUFF CONTOUR - The specified shape of a buffed area. BELT EDGE INSERT - Helps optimize belt and body ply contours. BUFF(ING) - Removal of the previously vulcanized rubber surface. BELT OVERLAY - A reinforced fabric layer extending over the belts to reinforce the belt package. BUFF LINE - The dividing line in the cross section of a tire between the buffed surface of the original tire and the - Separation of the belts from the plies BELT SEPARATION new retread rubber. or tread, or from each other. BELTED BIAS - See TIRE, BELTED BIAS. BUFFED RADIUS - A measurement of the buffed surface curvature from shoulder to shoulder. BEVEL CUT - An angle cut used on tread or other splices. BUFFED SURFACE - A specifically prepared surface of a BEVELED SPLICE - An approximately 45° angle cut through tire casing or repair area to provide proper texture to the gauge which allows the tread ends to diagonally help promote adhesion to the new rubber. overlap themselves. BUFFED TEXTURE - That surface produced by buffing, BIAS PLY (DIAGONAL PLY) - See TIRE, BIAS PLY. rasping or cutting.

67 Common Retread and Repair Terminology - A Compendium of Industry Terms

BUFFER - A machine used to rasp the old tread from the CASING DISTORTION - Processing defect in which the casing. A powered rotary rasp provides a clean, even natural shape of the tire is deformed by constriction in surface for adhesion of the new tread rubber. matrix during the retreading process. BUFFING TEMPLATE - A machined device of a specified CASING PLY - See BODY PLY(IES). shape used to obtain the required buffed radius. CAUTION - Indicates a potentially hazardous situation BUILD-UP - Application of tread rubber or repair rubber which, if not avoided, may result in minor or moderate to a casing. injury; may also be used to alert against unsafe practices (ANSI Z535.3, Environmental and Facility Safety Signs). BUILDER - A machine used to apply and stitch tread rubber to a casing. CEMENT - An adhesive rubber compound usually dissolved in solvent used to provide building tack and BULGE - A protrusion or raised area, usually in the tire cured adhesion. May be brushed or sprayed on the buffed sidewall. surface. Some cements may be water-based. BUMPING - Opening and closing of mold to center a tire, CENTERLINE - Circumferential line at the center of the allow rubber to flow, and gases to escape. tire’s crown area; aids in centering of the new tread. - A 90° angle cut across the tread crown and CHAFER - Reinforcing material (rubber or fabric) in the BUTT SPLICE rim flange area to prevent chafing of the tire by the rim through the gauge which permits full matching of the parts. See BEAD REINFORCE. tread ends when they meet. CHAMBER - See AUTOCLAVE. BUTTONHOLE - Circular hole made at the end of an injury (usually a tear or split) that may help prevent propagation CHANNELING - Voids in the shoulder area between the of the injury. tread and the buffed surface. BUTYL RUBBER - A general purpose synthetic elastomer CHECK TEMPLATE - A precut pattern used to determine (rubber) produced by copolymerizing isobutylene with the contour of a buffed tire to check compatibility to a small amounts of isoprene. Butyl rubber has a high matrix. resistance to chemicals and low permeability to gases. Its permeability to air is 70% better than that of natural CHECK VALVE - A one-way valve used to prevent pressure rubber and for this reason is superior for tire tubes and loss or back flow. for tubeless tire inner liners. CHEMICAL CLEANER - A rapid-drying rubber solvent BUZZ-OUT - See SKIVE. for removing matrix lubricant, dirt, and other foreign material. CABLE - See CORD. CHEMICAL CURE - Vulcanization at room temperature CAD/CAM (CADAM) - A computer programmed activated by chemical agents without the application of system that aids in the design and manufacture of tires, heat from an outside source. equipment or facilities. CHEMICAL DAMAGE - Damage from petroleum products causing a softness or degradation in the sidewall rubber CALCIUM CHLORIDE (CaCl2) - Chemical added to prevent freezing of water ballast in farm tires. of the tire or in the liner. - A liquid capable of - A multi-rolled machine which impregnates CHEMICAL LEAK DETECTOR CALENDER detecting air not discernible by visual inspection. fabric or cord with rubber and/or forms a thin-layered sheet of rubber or other material. CHEMICAL RUBBER COMPOUND - A two-part rubber putty which, when mixed together thoroughly, begins CALIBRATE - To measure against and adjust to a standard. curing at room temperature. CALIPER - A device for measuring inside or outside CHEMICAL RUBBER GUM - An especially compounded dimensions. repair gum which cures at room temperature by chemical action. CAMELBACK - Former name for die-size rubber used in retreading. See DIE-SIZE (UNCURED RUBBER). CHEMICAL VULCANIZING CEMENT (CHEMICAL CURE CEMENT) - Cement which when used with compatible CARBIDE CUTTER / CARBIDE BURR - A rotary cutting tool. materials will produce a chemical cure. Carbide is a hard, metallic material. CHIPPER - A narrow band of fabric or steel cord located CASING - A used tire to which additional tread may be in the bead area whose function is to reinforce the bead attached for the purpose of retreading. area and stabilize the lower sidewall.

68 Common Retread and Repair Terminology - A Compendium of Industry Terms

CHLOROBUTYL (BROMOBUTYL) - Butyl rubber with a CROSS-SECTION WIDTH - See SECTION WIDTH. chlorine atom bonded to the butyl backbone. Chloro- butyl has a high air retention and good heat stability; is CROWN - The middle part of the tread. It is the section frequently used in tire innerliner compounds. Bromobutyl between the should areas of a tire. is another polymer used with equivalent properties. CROWN PLY - A layer or layers of ply material underneath CHUNKING - Also known as “chipping” or “chip chunk”. the tread surface that stabilizes the tread area and The breaking away of pieces of the tread. restricts growth of the tire casing. CIRCUMFERENTIAL BREAK - A break parallel to the beads CROWN RADIUS - See TREAD RADIUS. in the sidewall area. CROWN WIDTH - Term used as one of the three measure- CIRCUMFERENTIAL CRACKS - Continuous cracking on the ments of die size rubber. Also referred to as TREAD tire or in the grooves of the tire tread running parallel to WIDTH. the beads. CURE - The process of vulcanization of rubber by applying COLD INFLATION PRESSURE - The pressure that exists heat and pressure over a period of time. See CHEMICAL when the tire has not been run for at least three hours CURE. or has been driven less than one mile at moderate speed. These are the recommended conditions at which CURE RATE - The speed at which a compound cures and to measure tire pressure and reflects the reference develops its physical properties. pressure(s) used by industry standardizing bodies. CURE RATE FACTOR (CFR) - Used in curing calculations. COLD PATCH - See REPAIR UNIT and CHEMICAL CURE. CURE TIME - The length of time established to achieve a desired cure state. COLD PROCESS RETREADING - See PRECURE PROCESS. CURING RIM - The rim used to support the tire and/or the COLLAPSIBLE RIM - A rim used in retreading that can be tube in place while curing. Not intended for vehicle/road folded and unfolded for insertion into the tire, where it use. holds the curing tube in place, which exerts pressure on the tire interior. CURING TUBE - A special, heavy-duty tube placed within the tire while curing the retread or repair. COMPOUND - A thorough mixture of natural and/or synthetic polymers and various ingredients designed for CUSHION GUM (BONDING GUM) - A tacky, rubber specific components of the tire. compound used for adhesion of tread rubber, undertread repair, build-up of other repairs or on the bottom of some CORD - The fabric or steel filaments forming the repair units. reinforcement structure in the tire. CUT-OFF RIB - The rubber pattern left on the casing as a CORD ANGLE - The angle at which the cord(s) within a tire result of the mold’s stop or flow ring. See FLOW STOP and crosses the centerline of the tread face. STOP RING. CORROSION - The oxidation of steel cords and/or rim DANGER - Indicates an imminently hazardous situation components. which, if not avoided, will result in death or serious injury; limited to the most extreme situations (ANSI Z535.2, Envi- COST-PER-MILE - Total cost including repairs and retreads, ronmental and Facility Safety Signs). if any, divided by total mileage obtained from tire. In some cases “down time” may be taken into consideration. DEBAGGER - A device for inserting and removing curing tubes from a retreaded tire. CRACKING (TREAD or GROOVE) - Any tearing within the tread or tread grooves. DEFLATION - When a tire is in a state of collapse due to the absence of inflation pressure. CROSS PLY - Sometimes used to refer to a bias ply tire. See TIRE, BIAS PLY. DELAMINATION - A somewhat smooth separation between layers of material. CROSS RIB TIRE - A deep tread, drive wheel position tire with deep molded grooves that extend radially from near DELUGGER - A machine used to cut the lugs from tires the center of the tread into the shoulder area. prior to buffing. CROSS-SECTION - A section or piece of the tire cut off at DESIGN RIM WIDTH - The measuring rim width assigned right angles to the bead. to each tire size designation to determine basic tire dimensions. CROSS-SECTION SIZE - External sidewall to sidewall measure of tire exclusive of ribs. DETREADER - A machine that delugs and buffs a tire.

69 Common Retread and Repair Terminology - A Compendium of Industry Terms

DIAPHRAGM - See ENVELOPE. EXTRUDING - Process of forming uncured rubber compound into a given shape by passing through an DIE - Two piece metal plate with an orifice through which extruder. rubber compounds are shaped when forced through the opening by an extruder. FABRIC FATIGUE - Fabric degradation and resultant loss of tire cord strength due to repeated flexing, accentuated by DIE SIZE (UNCURED RUBBER) - Dimensional size designa- overloading and/or under inflating. tion for retread rubber. (Example -72-76-18) First two digits are crown width in inches and 8ths. Second two FAST-CURE GUM - Rubber compound which cures at a faster digits give base width in inches and 8ths. Third number is rate than retread rubber, and is tested at 260°F (127°C). thickness in 32nds of an inch. FEATHERING - Reduction in thickness to allow a smooth DIE SIZER - Machine used to extrude tread rubber and transition to match the contour of the adjacent material. build tires for retreading. FILLER PLUG - See REPAIR PLUG. DIE SWELL - Swelling or expansion of rubber during FILLER STRIP - An uncured calendered rubber strip extrusion. (usually fast-curing) used under the tread when added thickness is needed in retreading. DOT - The letters “DOT” (Department of Transportation) precedes the tire identification number (TIN) and must FILLER GUM (FILLING STOCK, REPAIR GUM) - An uncured be molded into the sidewall of all over-the-highway tires rubber compound (usually fast-curing) used to fill in low produced by tire manufacturers and retreaders that spots or repairs on a casing. distribute and sell tires in the U.S. This mark certifies that the tire meets or exceeds all applicable safety standards FINGER BULGE - A localized distortion normally in the established by the Code of Federal Regulations, Federal sidewall indicating a slight opening between body cord Motor Vehicle Safety Standards. spacing or can be caused by a penetrating injury. DRYER (DRYING ROOM) - Equipment or an enclosed FINISHED BUFF - See BUFFED TEXTURE. space (usually heated) used to remove moisture from casings prior to inspection and processing. FLAP - A cured, shaped rubber strip which fits inside the tire to protect the tube from pinching by beads or rubbing DUROMETER - A device to measure the hardness of on rim. Normally used with tube-type tires. rubber. The term is also applied to the readings obtained FLASH - Excess rubber squeezed out between edges of with this device; for example, a tire tread may be defined mold during curing process. as 60 durometer, which means that it shows this degree of hardness when tested with the durometer. FLEX AREA - Circumferential area in a tire where maximum bending or flexing occurs. DUROMETER HARDNESS - A numerical value obtained from the durometer that measures the resistance to FLEX BREAK - A circumferential break in fabric cords indentation (hardness) of the rubber. usually parallel to the beads in the mid-sidewall area. EDGE LIFTING - A separation of the outer edge of the FLEX CURE - Proprietary system using uncured tread tread from the casing’s shoulder. rubber and flexible rubber molds to produce a retread in a pressure curing chamber. ENCAPSULATED - One material enclosed by another material. FLEX ZONE - Reference to the area of a radial tire from the shoulder apex to mid-sidewall where only the body ENVELOPE - A flexible rubber covering used to cover and ply supports the casing profile. retain air for a tire being retreaded. FLOW CRACK(ING) - A surface crack caused by improper ETRTO - European Tyre and Rim Technical Organisation. rubber flow when a tire (or retread rubber) is shaped in This group develops European standards for tires, rims, the curing process. and valves. FLOW STOP - A design feature in the mold which stops EXTRUDATE - Uncured rubber compound after being the flow of new retread rubber. See STOP RING. passed through the die of an extruder. FOOTCANDLE (FC) - A unit of illuminance or illumination, EXTRUDER - A machine that shapes a rubber compound, equivalent to the illumination produced by a source of one candle at a distance of one foot and equal to one by the process of extruding, into a usable, heated form lumen incident per square foot. (Example: strip or die size). FULL CAPPING/TREADING - A mold cure process that EXTRUDER GUN - A small hand-held portable extruder replaces the sidewall shoulder area and the tread area. This used for spot application of heated rubber to the casing. process would cover to the stop ring of the mold or matrix.

70 Common Retread and Repair Terminology - A Compendium of Industry Terms

FULL-CIRCLE MATRIX (MOLD) - Mold or curing band for the tire, or a break usually in the shape of an “I” which retreading made in a continuous circle as opposed to a can be seen from outside of the tire. segmented mold. INFLATION (PRESSURE) - The minimum cold tire inflation FULL-SERVICE REPAIR FACILITY - A facility with the proper pressure required for specific load and speed conditions. equipment, repair materials, and trained personnel to See COLD INFLATION PRESSURE. perform a full range of tire repairs -- such as puncture, spot, reinforcement, and section -- off the rim. INJURY (INJURIES) - Any damage caused by a penetrating object or severe scuff or impact. GAUGE - Thickness, usually expressed in 32nds of an inch for tread rubber or by the decimal system for repair gums INJURY SIZE - Widest opening in the cord body after (millimeters for metric system). See TREAD DEPTH GAUGE. skiving and buffing. GG RING - See GUIDE RING (RIB). INNER LINER (LINER) - The layer(s) forming the inside surface of a tubeless tire that contains the inflating GLYCERINE - A syrupy liquid used in air bags to help medium within the tire. prolong the life of the rubber. It should only be used if specifically prescribed on the instruction tag from the air INNER LINER REPAIR MATERIAL - A special repair bag manufacturer. material specifically for inner liners. GREEN TIRE - A built tire (new or retreaded) before being INNER LINER SEALANT - Liquid or semi-solid material cured. which is used to coat the inner liner. GROOVE - Space between two adjacent tread ribs or lugs. INNER LINER SEPARATION - The parting of the inner liner from the body ply material. GROOVE CRACKING - See CRACKING. INNER TUBE (TUBE) - An airtight rubber membrane GROOVE VOID DEPTH - Measurement of the perpendicular (bladder) placed inside the casing of a pneumatic tire to distance from a real or calculated reference, defined by hold air. edges of two adjacent ribs (lugs) to the lowest point of contact in the groove (void). INSIDE CURING RIM - A metal support for a curing tube, fitting inside the tire, not intended for vehicle use. See GROOVING (SCULPTING) - The cutting of a tread design COLLAPSIBLE RIM. into tread rubber when a design does not already exist. INSPECTION (TIRE) - The process of checking and GUIDE RING (RIB) - A rib of raised rubber running around assessing the suitability of a tire or casing for further a tire just above the bead to indicate proper mounting stage of manufacturer or service. and seating of the tire on the rim. INTERNATIONAL TIRE AND RUBBER ASSOCIATION (ITRA)- GUM STRIP - A thin gauge piece of rubber normally Formerly the ARA. See TIRE INDUSTRY ASSOCIATION. wrapped around the end of a cut fabric or steel belt ending to relieve stress. JATMA - Japan Automobile Tyre Manufacturers Associa- tion. This group develops Japanese standards for tires, HARDNESS TEST - Measure of resistance to penetra- rims and valves. tion of rubber by use of durometer. See DUROMETER HARDNESS. KETTLE CURE - See AUTOCLAVE. HEAT CURE - Repair unit activated by heat and pressure. KEVLAR - A high-strength synthetic fiber-type material used to form a ply cord and is a registered trademark of HEAT PAD (HEAT BOOSTER) - An electric heating unit DuPont. which provides heat to cure repairs. KILOPASCAL (kPa) - A unit of pressure. 1 kPa = 0.1450 psi. HEEL - See BEAD HEEL. See USEFUL CONVERSION FORMULAS on page following industry terms. HOLLAND CLOTH - A completely filled, woven fabric with a smooth finish on both sides, used to separate rubber KINKED BEAD(S) - Damage resulting in a sharp permanent from adjacent materials. bend in the bead wire at one or more points around the circumference of the bead. HOT CAPPING - See MOLD CURE RETREAD PROCESS. LIGHT TREAD - Failure of tread stock to completely fill the HYSTERESIS - Measure of energy loss expressed in degree mold, especially at the edges of design elements. of temperature build up. LINER - This term can also refer to protective poly IMPACT BREAK - In a tire, a break usually in the shape of materials used for packaging precured tread rubber. See an “X”, “Y” or star, which can be seen from the inside of INNER LINER.

71 Common Retread and Repair Terminology - A Compendium of Industry Terms

LIQUID BALLAST - A liquid solution (usually calcium MATRIX SKIRT - The sidewall flange of the matrix. In a chloride) placed inside a tire to add unsprung weight. short-skirt matrix, the flange extends from the shoulder to the flow stop, and in a long-skirt matrix, it extends LOAD INDEX - A numerical code associated with the below the flow stop. maximum load a tire can carry at the speed indicated by its speed symbol under specified conditions. MILL - Machine composed of two large iron or steel counter rotating rolls, used to warm, mix, and blend LOAD RANGE - A letter designation (example A, B, C, D, rubber. E, etc.) following tire size designation, used to identify a given size tire with its load and inflation limits when used MILLIMETER (mm) - A metric unit of measure. 1 mm = in a specific type of service, as defined in the Tire and Rim 0.039 inches (or 25.4 mm = 1 inch). See USEFUL CONVER- Association, Inc. tables. SION FORMULAS on page following industry terms. LOAD RATING - The maximum load a tire is rated to carry MILLING - Process of breaking down raw rubber and for a given usage at a specified cold inflation pressure. blending with curative ingredients and other compounds. LOCAL SERVICE - An application in which operation is MODULE - Small pressure chamber used in precure limited to speeds not to exceed 55 mph for not more than systems holding one to four tires at a time. 60 continuous minutes. MODULUS - The force expressed in pounds per square LOW PROFILE (ASPECT RATIO) - A tire in which the ratio inch (or kilograms per square centimeter) required to of cross-section height to section width (80% or less) is stretch a piece of rubber to a given elongation. lower than that of a conventional tire. MOISTURE BLOWS - Ply separations caused by the LOW-TEMPERATURE GUM - A rubber compound which expansion of moisture in the casing when heated during cures at a faster rate than fast-cure gum, usually tested at curing; usually shows up when removed from matrix. 260°F (127°C) or 200°F (93°C). MOLD - The heated cavity in which tires, retreads, and LUBRICANT - A substance that lessens or prevents friction repairs are vulcanized. Includes the curing chamber, or difficulty and eases release. matrices, and adjusting devices. LOCK RING - Removable, split rim locking ring that holds MOLD BLOW - A porous condition caused by a loss of rim flange on a multi-piece rim. pressure or under cure. LUG - A discontinuous tread element. MOLD CURE RETREAD PROCESS - The fitment and vulcanizing of uncured tread rubber to a properly buffed LUG REINFORCEMENT - Supporting tie bar or buttress and sized casing in a mold or matrix system. designed to reinforce tread elements. MOLD LUBRICANT - Material used as release agent to LUG TEARING - Ripping of the lug, sometimes resulting in facilitate removal of the tire from the mold after curing. removal by violent operation or mechanical interference. MOLD SIZING - Measuring the tire casing to determine LUX (LX) - A unit of illumination, equivalent to 0.0929 proper mold fit. Usually a combination of bead-to-bead or foot-candle and equal to the illumination produced by cross section and tire circumference is used. luminous flux of one lumen falling perpendicularly on a surface one meter square. MOLDING SHRINK - Shrinkage in rubber gauge as the rubber is vulcanized, usually within a 2-3% range. “M” DIAMETER - Diameter at the base of the tread design; matrix undertread diameter. MONSANTO RHEOMETER (ODR) - Instrument used to determine curing characteristics of rubber compounds. MANDREL - A curved support inserted in a tire to prevent the casing from collapsing while building and curing a MOONEY SCORCH - See SCORCH TIME. repair. MOONEY VISCOSITY - Common expression for uncured MANUFACTURER (TIRE) - The name of a company or compound plasticity measured by a laboratory machine. wholly owned subsidiary making the tire. NAIL HOLE - See PUNCTURE. MASTER BATCH - Homogeneous mixture of rubber and other materials for use as raw material to produce tread NATIONAL TIRE DEALERS & RETREADERS ASSOCIATION compound. (NTDRA) - See TIRE INDUSTRY ASSOCIATION (TIA). MATRIX (MATRICES) - Aluminum or steel rings or NON-FILL - Failure of rubber to properly fill the matrix segments which form the cavity in which the retread is during cure, resulting in imperfectly formed tread actually cured and from which the tread design is formed. elements and rounded lug edges.

72 Common Retread and Repair Terminology - A Compendium of Industry Terms

NON-SKID DEPTH - See TREAD DEPTH. OZONE CHECKING - Formation of fine cracks in surface of rubber due to ozone in the environment. OFF-CENTER TREAD - A tread that is not symmetrically distributed from the centerline of the casing; or lateral PADDING GUM - Heat resistant rubber used under tread displacement of the tread with respect to the centerline rubber to build up its size for mold fit. See FILLER GUM. of the casing. PANTOGRAPHING - Angular movement of diagonal plies OFF-REGISTER TREAD - A tread with the design off (i.e., in tire shaping or deflecting. not matching up) at the mold parting line either circumferentially or radially. PATCH - See REPAIR UNIT. OPEN SPLICE - Any parting of a splice. PATCH-PLUG - Combination of a patch repair unit and a repair plug. See REPAIR UNIT. OPTIMUM CURE - That state of cure at which the rubber compound exhibits the most satisfactory physical PEAKING - A condition, usually in the cushion, resulting properties. from local material starvation and excessive flow from adjacent areas. OCCUPATIONAL HEALTH & SAFETY ADMINISTRATION (OSHA) - The federal agency responsible for establishing PENETRATION - Damage to a tire caused by a piercing and enforcing safety and health regulations in the object that may or may not puncture the inner liner of workplace. the tire casing. ORBITREAD MACHINE - A combined tuber-builder that PERFORATED POLY - Polyfilm that covers the tread to applies tread rubber to a tire in ribbon form, and in a create lubrication between the tread and envelope during spiral configuration. curing. OUT OF ROUND - The eccentricity of a tire or tire and PERFORATION - Damage completely through a tire wheel assembly. caused by a piercing object. OVERALL BUFF WIDTH - The specified amount of buff PERMANENT TIRE REPAIR - An off-the-wheel tire repair required to properly fit a tread to a casing. performed by a trained technician. The tire is fully inspected and a repair, which meets the manufacturers’ OVERALL DIAMETER (O.D.) - Measurement of a tire when recommendations for injury size and is completed using inflated and mounted on rim. Or, the measurement used industry approved procedures, is installed on the inner to size a buffed tire (while the tire is inflated) usually liner of the tire after the penetrating injury is filled with checked by using a diameter tape rule. rubber. OVERCURE - Curing in excess of optimum cure. Excessive PLASTICITY - Resistance of an uncured rubber compound overcure can result in the deterioration of certain to distort or flow under pressure. physical properties. See REVERSION. PLASTICIZER - A chemical compound added to natural OVERFLOW - Excessive tread compound at the mold and synthetic rubber to impart softness, flexibility or parting line or at the edge of the matrix skirt which resiliency. should be trimmed or buffed off. See FLASH. PLY (PLIES) - A layer of rubber-coated parallel cords. OVER INFLATION - Inflation of a tire beyond the tire’s recommended pressure. PLY ADHESION - Strength of bonding between adjacent plies, usually expressed as the force required to separate OVERLOADING (TIRE)- A condition in which the vehicle them. is carrying more weight than the tire is rated to carry at a specific inflation pressure. Tire overloading can be PLY RATING - An indication of tire casing strength and dangerous and is not recommended. However, note that load-carrying capacity, expressed as numbers, letters, tire load capacity can be increased in certain cases by and/or symbols; does not necessarily represent the increased inflation or control to lower speeds. See TIRE number of cord plies in the tire. See LOAD INDEX and AND RIM ASSOCIATION YEARBOOK. LOAD RANGE. OXIDATION - The reaction of oxygen with rubber or steel, PLY SEPARATION - The loss of adhesion between adjacent usually evidenced by a change in the appearance (discol- plies. oration) of the surface, a change in physical properties, corrosion or wire rust. PLY TURN-UP - The part of the body ply that wraps under the bead bundle and ends in the tire sidewall. OZONE - A form of oxygen which accelerates aging and weathering in tires. PNEUMATIC PRESSURE - Air pressure.

73 Common Retread and Repair Terminology - A Compendium of Industry Terms

POLYFILM - A thin strip of polyethylene applied to the R.A.R. - Returned As Received. A casing rejected for precure tread surface, after building, that helps to extend retreading. the life of an envelope and helps eliminate sticking to the cushion. RADIAL CRACKING/CRACKS - Cracks in the shoulder or sidewall of a tire, running perpendicular to the beads. POROSITY - Small air bubbles created when rubber is cured at insufficient pressure and/or time. RADIAL PLY - See TIRE, RADIAL. POTENTIOMETER - A voltmeter that reads the extremely RADIAL RUNOUT - A measure of out-of-roundness; tested low voltage developed at the thermocouple junction by rotating the inflated tire and observing or measuring and thus shows the temperature. Usually read directly in how far the surface of the tread varies from a true circle. degrees of temperature. RADIAL SPLIT - See BREAKS. POUNDS PER SQUARE INCH (psi) - A measurement of pressure. 1 psi = 6.895 kPa (or 1 kPa = 0.1450 psi). See RADIAL SPLIT BREAK - A break of the sidewall perpendicular USEFUL CONVERSION FORMULAS on page following to the beads that has not damaged the cords. industry terms. RADIAL TIRE - See TIRE, RADIAL. PRECURE PROCESS - The process of using precured tread and bonding it to a prepared casing with a thin layer RAM EXTRUDER - Hydraulically operated batch loading machine for producing various extruded shapes of rubber. of cushion gum (compound reach in natural rubber). Temperatures used range from 210°F (100°C) to 320°F RASP - A tool with raised points used for removing and (161°C). texturizing rubber surfaces. PRECURED TREAD - Tread which is vulcanized with the REAM - To clean an injury or hole prior to repair. tread configuration molded into it prior to being placed on the buffed casing. RECAPPING - An improper term for retreading. Often refers to process known as “top-capping” in which rubber PRECURED TREAD CUSHION GUM - A tacky rubber is applied to tread surface only. compound used to bond the precured tread to the prepared surface. REGULATOR (REDUCING VALVE) - Pressure-regulating device used for controlling steam or air pressure to a PRE-DRYING - Drying of a tire in a heated room, chamber desired level. or device to remove moisture before retreading. See DRYER. REGROOVING - The cutting into an existing tread design to a depth greater than that provided by the new tire PRESS (LOADING) - A machine designed to open and manufacturer or retreader. 49 CFR Federal Motor Vehicle close a matrix, load, and eject retreaded tires. Safety Standards Part 569 regulations apply. PRESSURE TREAD - Proprietary system for applying REINFORCED SHOULDER REPAIR (RSR) - Procedure extruded, patterned, uncured tread onto a buffed casing, guidelines for size selection and placement of repairs for without use of molds, in a single operation. penetrations up to 5/16” in the shoulder of truck tires. PROCESSING - Various stages in the production of a new REINFORCEMENT - Material, usually rubber and fabric, or retreaded tire. vulcanized to the tire to add strength to the tire cord body at an injury. PROFILE DIE - An extruded die size configuration other than a rectangle. REINFORCEMENT REPAIR - See REPAIRED TIRE. PROTECTOR PLY/BELT - A ply added primarily to protect RELUGGING - A method of retreading agricultural and the structural belts, which may be removed during off-the-road tires using hand-applied preformed lugs and retreading (if extensively damaged). kettle cure. See BAND LUGGING. PUNCTURE - A penetration through the tire, made by a REMOLDING - A bead-to-bead retreading process by small object. which tread and sidewalls are renewed to give a new tire appearance. PUNCTURE REPAIR - See REPAIRED TIRE. REPAIR GUM - A soft, tacky, usually fast-curing rubber PYROMETER - An instrument to measure temperatures, compound used in tire repairing; available in sheet, strip usually by the generation of electric current by a and rope form. Typically used in section and spot repairs. thermocouple when acted on by direct heat or an infrared sensor. Commonly used to measure surface mold REPAIR MATERIAL - Specifically designed material (repair temperatures or (if a penetrating needle is used) tread units, repair gums, cements, etc.) used during the repair rubber temperatures. process of a tire or tube.

74 Common Retread and Repair Terminology - A Compendium of Industry Terms

REPAIR PLUG - Specifically designed material (stems, RIM - The outer support part of a wheel, usually metal, repair gums, cements, etc.) used during the repair for a tire or a tire and tube assembly on which the tire process of a tire. beads are seated. See WHEEL. REPAIR SEALANT - Liquid or semi-solid materials used to RIM DIAMETER (NOMINAL) - The named rim diameter cover over-buffed areas around repair units. within 0.5 inch increments, (22”, 22.5”, 17.5”, etc.). REPAIR UNIT (PATCH, PLUG, PATCH/PLUG COMBO) - A RIM FLANGE - The part of the rim that supports the bead specially designed unit made of fabric and/or rubber that above the heel and resists lateral internal pressure. is applied to a tire or tube to restore tire and/or tube integrity. ROLLING RESISTANCE - The resistance of a tire to free rolling. REPAIRED TIRE - Any tire with punctures, cuts or other ROPE RUBBER - Uncured repair gum supplied in continu- types of injuries that have been reconditioned as required ous cylindrical form to be used in a hand-held extruder, to provide additional service life. generally for tire repairing. Common repair types are: RUBBER BUFFINGS (BUFFING DUST) - Loosened rubber Puncture Repair: Off-the-wheel repair(s) of any injury particles from buffing the tire. caused by a penetrating object. (NOTE: The type of repair is determined by size, depth and location of RUBBER CEMENT - See CEMENT. injury.) RUBBER HARDNESS - Resistance of rubber to penetra- Reinforcement Repair: Repairs, larger than a rein- tion by blunt point. Durometer “A” hardness tester is forced puncture repair, made to the casing when an commonly used to measure hardness. See DUROMETER injury has extended through 25% but less than 75% HARDNESS. of the tire body, requiring both filling material and reinforcing patch. RUBBER MANUFACTURERS ASSOCIATION (RMA) - See US TIRE MANUFACTURES ASSOCIATION (USTMA). Section Repair (Bias/Radial Tire): Repairs, larger than a reinforced puncture repair, made to the casing RUBBER SEPARATION - The lifting or parting of when an injury has extended through 75% or more component parts from adjacent rubber parts of the tire. of the actual plies, or completely through the casing RUN FLAT CONDITION - Tire damage resulting from in the tread or sidewall areas. The damaged cord is operating with low or no air pressure, sometimes removed and new cord is replaced in the form of a identified by repetitive liner cracking or discoloration. patch. (NOTE: The type of repair is determined by size, depth and location of injury.) RUN-FLAT TIRE - A pneumatic tire designed to carry the load for a limited distance if the tire is deflated. Spot/Surface Repair (Bias Tire): Repairs made to the casing by vulcanizing rubber to a tire without using RUST - See CORROSION. reinforcing materials and the injury penetrates less than 25% of the body plies. SCORCH (CURED RUBBER) - A soft, tacky surface that occurs during the buffing or skiving processes due to Spot/Surface Repair (Radial Tire): Repairs made to excessive heat. Bonding/adhesion will be adversely the casing by vulcanizing rubber to a tire without affected by scorched rubber. See REVERSION. using reinforcing materials and the injury does not extend to the cords. SCORCH (GREEN RUBBER) - Premature vulcanization of rubber caused by excessive heat during processing. RESILIENCE - Capacity of rubber to recover its original Scorched compounds will not mold properly nor develop size and shape after deformation. satisfactory adhesive properties. RETREADABILITY - Ability of the tire casing to be SCORCH TIME - Time (in minutes) as measured by a retreaded and provide acceptable performance. laboratory test instrument at which the compound starts to cross-link or vulcanize. It relates to the shelf life and RETREAD TIRE (RETREADING) - A casing to which new processability of the compound. tread rubber has been vulcanized to the prepared surface to extend the service life of the tire. SCRAPER - A hand-held tool used to remove contaminants from the inner liner surface prior to mechanical buffing. - A separation between the tread RETREAD SEPARATION - See REPAIRED TIRE. rubber and the buffed tire casing. SECTION REPAIR SECTION WIDTH (CROSS-SECTION WIDTH) - The REVERSION - Deterioration of a rubber compound’s maximum width of the inflated tire including the normal physical properties due to an excessive accumulation of sidewalls, but not including side ribs, scuff bars or heat history. decorations.

75 Common Retread and Repair Terminology - A Compendium of Industry Terms

SECTIONAL BAG (AIR-STEAM) - A rubberized fabric bag, contaminants and increase the tackiness of uncured which is placed inside a tire and inflated in a section mold, rubber surfaces. that applies pressure for curing to the injured/repaired area. SPACER RING (SPACERS) - A ring inserted between two halves of a matrix which enables the matrix to handle SEGMENTED MOLD - Multi-piece mold segments which tires of the same diameter, but with greater tread widths open to insert a tire and then close together to form a and larger cross sections. continuous circle. SPECIFICATION - Written requirements for process or SEPARATION - Lack of adhesion between any adjacent materials. materials in a tire. SPECIFIC GRAVITY - Ratio of the weight of a given volume SET-UP - Premature vulcanization of a rubber compound of any substance to that of the same volume of water. during process or storage. The higher the specific gravity, the denser or heavier the substance. SHEAROGRAPHY - A non-destructive inspection method using laser technology. SPLICE - The junction formed by joining the two ends of a tire component. SHELF LIFE - The recommended period of time (stated by the product’s manufacturer) for which that product may SPOT REPAIR (BIAS) - See REPAIRED TIRE. be applied and/or utilized before it degrades and/or is no longer effective or serviceable. SPOT REPAIR (RADIAL) - See REPAIRED TIRE. SHOULDER AREA - Transitional area between the tread SPOTTER (SPOT PRESS) - A small heat vulcanizing unit and sidewall (including the outer edge of the tread used in localized repairing tires and tubes. and uppermost sidewall area of the tire); in radial tires includes the outer edges of the belts. SPREADER (TIRE SPREADER) - A machine used for spreading the beads of a tire during inspection and/or SHOULDER RADIUS (BUFFED) - The buffed contour as repairing. applied to the shoulder area of the tire. STANDARD PROFILE (ASPECT RATIO) - Tube-type tires SIDEWALL AREA - That portion of a tire between the that are 100 aspect ratio; tubeless tires that are 90 aspect tread and bead area. ratio. SIDEWALL RUBBER - A non-structural element designed STANDARD RIM - A rim that meets the precise measure- to protect the body ply from contact with damaging ments specified by the Tire and Rim Association, Inc., or objects or weathering. other standardizing bodies. SIDEWALL SEPARATION - A lack of adhesion between STEAM TRAP - An automatic device for discharging the components in the sidewall. accumulated water of a steam pipe or vessel, while maintaining pressure. SIPE - Relatively small straight, angular or curved slots, other than grooves, molded or cut in the tread surface. STEEL BELT PACKAGE - The layering of multiple steel belts designed to stabilize the tread, provide strength, and SKID DEPTH - The distance between the tread surface protect the air chamber from punctures. and the deepest groove as measured in the mold. See TREAD DEPTH. STICKLEBACK - A rounded metal hand tool with raised points used to clean and ream injuries in bias ply tires. SKIM (SKIM COAT) - Rubber surrounding ply fabric or steel cords. STIPPLE (STIPPLING) - To aggressively apply and work in cement with a brush to a buffed surface or exposed cords. SKIRT - See MATRIX SKIRT. STITCHER - A hand held tool (or power equipment) used SKIVE (SKIVING) - The removal of injured or damaged for stitching. See STITCHING. materials. STITCHING - A procedure of applying pressure to remove SLAB STOCK - Rubber compound cut and taken from a trapped air and improve rubber contact for better mill in wide, thick strips or sheets. adhesion. SOAPSTONE - A soft talc-like powder used as a mold STOP RING - A design feature in the mold which stops the release agent or as an anti-stick. flow of new retread rubber. See FLOW RING. SOLVENT (RUBBER SOLVENT) - A liquid which will soften STRIP RUBBER - Uncured rubber in strip form most and dissolve uncured rubber, dilute cement, remove commonly used in cold feed extruders.

76 Common Retread and Repair Terminology - A Compendium of Industry Terms

STRIPPING STOCK - An uncured rubber stock used to designers and manufacturers of motor vehicles, aircraft extend or build up an area. and other wheeled vehicles and equipment, and govern- mental and other regulatory bodies. STRUCTURAL PLIES - Body and belt plies that contribute to casing strength. TIRE ASSOCIATION OF NORTH AMERICA (TANA) - Formerly NTDRA. See TIRE INDUSTRY ASSOCIATION. TACK - Stickiness of a rubber surface. TIRE INDUSTRY ASSOCIATION (TIA) - TIA was created out TALC - See SOAPSTONE. of the merger between TANA and ITRA. This group represents all sectors of the North American replacement tire TECHNICIAN - A person who has undergone a formal, market and provides technical assistance and training to structured training program and demonstrates the ability the tire and transportation industries in all areas relating and skill to perform specific technical functions. to tires and wheels, including tire service, retreading, repairing, and rubber recycling. TEMPLATE (BUFFING TEMPLATE) - A pattern used as a guide in repairing and retreading tires. In repairing, it TIRE PAINT - A black paint, compatible with the tire, used serves to outline the area to be buffed inside the casing. to enhance the appearance of a tire. In retreading, it is used to determine the correct contour of the buffed casing. TIRE RETREAD AND REPAIR INFORMATION BUREAU (TRIB) - An industry-supported association dedicated to TEMPORARY TIRE FIX - A system capable of addressing a the recycling of tires through tire retreading and repairing. through-the-tire penetration (or puncture) by restoring and maintaining air pressure to provide temporary TOLERANCE - The amount of variation allowed from a mobility of the tire. None of these methods are consid- specification. ered permanent tire repairs and may have speed or distance warnings on the package labels. Temporary tire TOP CAPPING - A mold cure retread process where only fix methods include (but may not be limited to): the tread is replaced. • Canisters containing pressurized foam which is TREAD - That portion of a tire that comes in contact with applied through the valve stem. the road surface. • Sealant kits that include a compressor and liquid media applied through the valve stem. TREAD DEPTH - The distance measured from the tread • A rubberized string or rope ‘plug’ installed in surface to the bottom of the grooves in a tire. the penetrating channel. TREAD DEPTH GAUGE - Instrument used for measurement of depth of tread design grooves in 32nds of an inch or in TEXTURE - See BUFFED TEXTURE. millimeters. THERMOCOUPLE TEST - A cumulative heat study using TREAD DESIGN - The pattern/design on the tire’s tread. special equipment to determine the proper cure time. TREAD GROOVES - The space between two adjacent TIE BARS - Bridge of rubber molded across base of tread tread ribs, lugs or bars. groove to stabilize some designs. TREAD GUM - A rubber compound designed to make a TIRE - See below. tread-area repair. TIRE, BIAS PLY/DIAGONAL - A pneumatic tire in TREAD RADIUS - A measure of the tread surface which the ply cords extending to the beads are laid at curvature from shoulder to shoulder. alternate angles substantially less than 90° angle to the center line of the tread. TREAD RIB - A continuous circumferential element of a tread design. TIRE, BELTED BIAS - A pneumatic tire with a bias ply casing and reinforcing belts extending from shoulder TREAD ROLLER - A roller, either manual or power, used to shoulder (usually at about a 25° angle). to help apply the tread rubber, remove trapped air, and improve adhesion. TIRE, RADIAL - A pneumatic tire structure in which the casing ply cords extend to the beads and are laid TREAD RUBBER - Compounded, natural or synthetic substantially at 90° angle to the center line of the rubber which is placed on a buffed casing and vulcanized tread, the casing being stabilized by an essentially to provide a new wearing surface. inextensible circumferential belt. TREAD RUBBER EXTRUDER - A machine designed to TIRE AND RIM ASSOCIATION, INC. (TRA) - Industrial asso- convert strip rubber into the required profile for applica- ciation of tire, rim and valve manufacturers. The purposes tion directly to the prepared casing. of TRA include the establishment and promulgation of interchangeability standards for tires, rims, and allied TREAD RUBBER (TREAD STOCK) - Rubber compound parts for the guidance of manufacturers of such products, which will replace the worn tire tread.

77 Common Retread and Repair Terminology - A Compendium of Industry Terms

TREAD RUBBER & TIRE REPAIR MATERIALS VENT HOLE - Small holes through the matrix, which allow air MANUFACTURERS GROUP (TRMG) - A national trade to escape and the rubber to flow and fill out the tread design. association for manufacturers of tread rubber and other retreading and repair materials. VENTING - A procedure performed on bias tires to facilitate the evacuation of air. TREAD SEPARATION - A lack of adhesion between the tread and the tire casing. VENTING, CASING - The act of partially perforating a bias tire through the outer rubber into the fabric, which allows TREAD WEAR - The normal loss of tread rubber due to trapped air to escape without loss of tire air-retention abrasion during tire service. ability. TREAD WEAR INDICATORS - Narrow bars of rubber molded VENTING, REPAIR - Cord or string used to allow air to at a height of 2/32-inch (2 mm) across the bottom of the escape from the repaired area and the fabric tire casing tread grooves. Tire tread worn to 2/32nds must be removed to the exterior of the tire. from service. VISCOSITY - See MOONEY VISCOSITY and PLASTICITY. TREAD WIDTH - The measurement across the tread face of a tire from shoulder edge, which defines the usable VOIDS - Air pockets within the structure of a tire width of the tread pattern. (Example: within or under the retread tread rubber.) TUBELESS - A pneumatic tire that does not require an VULCANIZATION - A chemical reaction which takes place inner tube for air retention. under appropriate time, temperature, and pressure. See CURE. TUBE-TYPE - A pneumatic tire that requires an inner tube for air retention. VULCANIZING CEMENT - See CEMENT and CHEMICAL VULCANIZING CEMENT for chemical curing. UNDERCURE - A condition which describes less than acceptable vulcanization. WARNING - Indicates a potentially hazardous situation, which if not avoided, could result in death or serious injury UNDERINFLATION - Tire having less than recommended (ANSI-535.2, Environmental and Facility Safety Signs). air pressure for the load being carried. Tire may build up excessive heat that may be dangerous and could result in WEATHER CHECKING - See OZONE CHECKING. sudden tire destruction. WHEEL - A combined rim and disk with a bolthole pattern UNDERTREAD - The gauge of the rubber between the for securing the tire assembly to the vehicle. bottom of the tread grooves and outermost ply or belt. WICK (WICKING MATERIAL) - Material or device used UNIFORMITY - A measure of the tire’s ability to run in precured retread systems to allow free passage of air smoothly and vibration free. Some examples of uniformity to atmosphere. In mold cure retreading, wicks may be measurements are, tire balance, out of round condition or built into tire using cord to allow trapped air in casing to radial and lateral run-out. escape during cure. UNSERVICEABLE - See R.A.R. WICKING - An act of air escapement from the tire casing or from under an envelope by means of the wick. US TIRE MANUFACTURES ASSOCIATION (USTMA) - The national trade association for the rubber products WIRE BRUSH - A hand held tool (or attachment to a industry. Its membership includes the major domestic power tool) that is used to clean and texturize surfaces tire manufacturers in the U.S. as well as manufactur- prior to retreading and/or repairing. ers of various rubber products including tires, hoses, belts, seals, molded goods, etc. USTMA represents the X-RAY - A non-destructive inspection method using industry before legislative and regulatory bodies as electromagnetic radiation passed through an object to well as provides consumer, scrap tire, statistical/market provide a photographic image. information analysis, technical, maintenance, and safety ZIPPER RUPTURE - As a result of being operated publications. significantly underinflated and/or overloaded, multiple - An extruded die size configuration, which ply cords break, thus creating a circumferential rupture VALLEY DIE in the upper sidewall area of a steel cord radial tire and from a cross view shows the shoulders higher than the is accompanied by instantaneous air loss and explosive center portion. force. (For inspection procedures, please see the RMA VALVE STEM - Tube through which air flows in or out of a TISB Vol. 33 Inspection Procedures for Zipper Ruptures tube or tubeless tire. in Steel Cord Radial Medium or Light Truck Tires and accompanying wall chart.) VENEERING - Application of a thin layer of rubber materials used in bead-to-bead retreading to cover the Reference: This glossary is based on RP-01/02-10 prepared sidewall. “Retread and Repair Materials Glossary of Terms”

78 Useful Conversion Formulas

79 Appendix 2

Radial Truck Tire Diagrams

Note: Appendix 2 is referenced in Retreading Medium Truck, Heavy Radial Truck, and Bus Tires

80 Appendix 2 cont.

Radial Truck Tire Diagrams

Note: Appendix 2 is referenced in Retreading Medium Truck, Heavy Radial Truck, and Bus Tires

81 Appendix 3

Measuring Injuries in Radial Tires

Note: Appendix 3 is referenced in Table IIA.

82 Appendix 4

Repairable Areas in Radial Tires

83 Appendix 5

Sidewall Labeling FEDERAL MOTOR VEHICLE SAFETY REGULATIONS 49 C.F.R. § 574.5 – TIRE IDENTIFICATION REQUIREMENTS

Note: Appendix 5 is referenced in Retreading Passenger Car and Light Truck Radial Fabric Body Ply Tires, in Retreading Light Truck Radial Steel Body Ply Tires Load Range E and Above, and in Retreading Medium Truck, Heavy Radial Truck, and Bus Tires.

84 Appendix 5 cont.

Sidewall Labeling

85 Appendix 6

Reinforced Shoulder Repair Unit Placement For any truck tire puncture repair, offset the repair unit over the injury within the designated window of the template, until the ends of the repair unit fall outside of the FLEX ZONE.

Note: Appendix 6 is referenced in Repairing Medium Truck, Heavy Radial Truck, and Bus Tires