Maintenance Manual MM-0401 Meritor WABCO Hydraulic Power Brake (HPB) System Revised 01-11 Service Notes About This Manual ț Maintenance Manual 38, Hydraulic ABS for Medium-Duty Trucks, Buses and Motor Home Chassis (C Version Hydraulic This manual contains maintenance procedures for Meritor WABCO’s ABS) Hydraulic Power Brake (HPB) system for trucks, tractors and buses. ț Maintenance Manual 39, Hydraulic ABS for Medium-Duty Trucks, Buses and Motor Home Chassis (D Version Hydraulic Before You Begin ABS) 1. Read and understand all instructions and procedures before ț Maintenance Manual MM-0677, Hydraulic Anti-Lock Braking you begin to service components. Systems (HABS) for Medium-Duty Trucks, Buses and Motor 2. Read and observe all Warning and Caution hazard alert Home Chassis (E Version Hydraulic ABS) messages in this publication. They provide information that can help prevent serious personal injury, damage to components, On the Web or both. Visit Literature on Demand at arvinmeritor.com to access and order 3. Follow your company’s maintenance and service, installation, product, service, aftermaket, and warranty literature for and diagnostics guidelines. ArvinMeritor’s truck, trailer and specialty vehicle components. Meritor WABCO publications are also available on our website: 4. Use special tools when required to help avoid serious personal injury and damage to components. www.meritorwabco.com Hazard Alert Messages and Torque ArvinMeritor’s Customer Service Center Symbols Call the OnTrac Customer Service Center at 866-OnTrac1 (668-7221). WARNING A Warning alerts you to an instruction or procedure that you Literature on Demand DVD (LODonDVD) must follow exactly to avoid serious personal injury and The LODonDVD contains product, service and warranty information damage to components. for ArvinMeritor and Meritor WABCO products. To order the DVD, visit Literature on Demand at arvinmeritor.com and specify CAUTION TP-0742. A Caution alerts you to an instruction or procedure that you must follow exactly to avoid damage to components. How to Obtain Tools and Supplies @ This symbol alerts you to tighten fasteners to a specified torque Specified in This Manual value. Call ArvinMeritor’s Commercial Vehicle Aftermarket at 888-725-9355 to obtain Meritor tools and supplies. How to Obtain Additional Maintenance TOOLBOXTM Software is available from SPX Service Solutions at and Service Information 1-800-328-6657. Publications Refer to the following publications for more information on servicing Meritor WABCO’s Hydraulic Power Brake (HPB) systems. Information contained in this publication was in effect at the time the publication was approved for printing and is subject to change without notice or liability. Meritor WABCO reserves the right to revise the information presented or to discontinue the production of parts described at any time. Meritor WABCO Maintenance Manual MM-0401 (Revised 01-11) Contents pg.i Asbestos and Non-Asbestos Fibers pg. 59 Section 6: Appendix 1 Section 1: Introduction Leak Check Procedure for Meritor WABCO HPB System Overview Check the HPB System for Brake Fluid Leaks System Components System Test 3 How the HPB System Works 60 Warning Lamps 61 Filling the Hydraulic Power Brake (HPB) Master Cylinder 5 Section 2: Wiring Diagram Reservoir HPB Wiring Diagram for Multiplex Vehicles 6 HPB Connector Diagram for Multiplex Vehicles 7 Section 3: Troubleshooting and Testing Testing the System Meritor WABCO TOOLBOXTM Software Hydraulic Power Brake Menus and Toolbars 12 Standard Testing Test Equipment: Volt-Ohm Meter (VOM) System Requirements and Component Tests Tire Size Range Voltage Check Standard Component Testing Indicator Lamps Sensor Adjustment Vehicle Test Drive 14 Section 4: Removal and Installation Removal Hydraulic Compact Unit 18 HCU Reservoir 20 HCU Accumulators 25 Electronic Control Unit (ECU) 28 Hydraulic Compact Unit (HCU) Relay Valve 30 Hydraulic Compact Unit (HCU) Pump 32 Master Cylinder Replacement Information Master Cylinder 37 Master Cylinder Reservoir 41 Master Cylinder Foot Brake Switch 42 Master Cylinder Fluid Level Sensor Switch Parking Brake Pressure Supply Valve 47 Low Pressure Hose 49 Wheel Speed Sensor Specification 50 Front Axle Wheel Speed Sensor 51 Rear Axle Wheel Speed Sensor 52 Section 5: Brake Bleeding Procedures 53 Brake Bleeding Procedures Pressure Bleed Procedures Master Cylinder Circuit 54 Brake Caliper Circuit 56 Spring-Applied/Hydraulic Release Parking Brake Circuit 57 Changing Hydraulic Brake Fluid Asbestos and Non-Asbestos Fibers ASBESTOS FIBERS WARNING NON-ASBESTOS FIBERS WARNING The following procedures for servicing brakes are recommended to reduce exposure to The following procedures for servicing brakes are recommended to reduce exposure to asbestos ber dust, a cancer and lung disease hazard. Material Safety Data Sheets are non-asbestos ber dust, a cancer and lung disease hazard. Material Safety Data available from ArvinMeritor. Sheets are available from ArvinMeritor. Hazard Summary Hazard Summary Because some brake linings contain asbestos, workers who service brakes must understand the Most recently manufactured brake linings do not contain asbestos bers. These brake linings may potential hazards of asbestos and precautions for reducing risks. Exposure to airborne asbestos contain one or more of a variety of ingredients, including glass bers, mineral wool, aramid bers, dust can cause serious and possibly fatal diseases, including asbestosis (a chronic lung disease) ceramic bers and silica that can present health risks if inhaled. Scientists disagree on the extent and cancer, principally lung cancer and mesothelioma (a cancer of the lining of the chest or of the risks from exposure to these substances. Nonetheless, exposure to silica dust can cause abdominal cavities). Some studies show that the risk of lung cancer among persons who smoke silicosis, a non-cancerous lung disease. Silicosis gradually reduces lung capacity and ef ciency and who are exposed to asbestos is much greater than the risk for non-smokers. Symptoms of and can result in serious breathing dif culty . Some scientists believe other types of non-asbestos these diseases may not become apparent for 15, 20 or more years after the rst exposure to bers, when inhaled, can cause similar diseases of the lung. In addition, silica dust and ceramic asbestos. ber dust are known to the State of California to cause lung cancer. U.S. and international Accordingly, workers must use caution to avoid creating and breathing dust when servicing agencies have also determined that dust from mineral wool, ceramic bers and silica are potential brakes. Speci c recommended work practices for reducing exposure to asbestos dust follow . causes of cancer. Consult your employer for more details. Accordingly, workers must use caution to avoid creating and breathing dust when servicing brakes. Speci c recommended work practices for reducing exposure to Recommended Work Practices non-asbestos dust follow. Consult your employer for more details. 1. Separate Work Areas. Whenever feasible, service brakes in a separate area away from other Recommended Work Practices operations to reduce risks to unprotected persons. OSHA has set a maximum allowable level of exposure for asbestos of 0.1 f/cc as an 8-hour time-weighted average and 1.0 f/cc averaged over 1. Separate Work Areas. Whenever feasible, service brakes in a separate area away from other a 30-minute period. Scientists disagree, however, to what extent adherence to the maximum operations to reduce risks to unprotected persons. allowable exposure levels will eliminate the risk of disease that can result from inhaling asbestos 2. Respiratory Protection. OSHA has set a maximum allowable level of exposure for silica of 0.1 dust. OSHA requires that the following sign be posted at the entrance to areas where exposures mg/m3 as an 8-hour time-weighted average. Some manufacturers of non-asbestos brake linings exceed either of the maximum allowable levels: recommend that exposures to other ingredients found in non-asbestos brake linings be kept DANGER: ASBESTOS below 1.0 f/cc as an 8-hour time-weighted average. Scientists disagree, however, to what extent CANCER AND LUNG DISEASE HAZARD adherence to these maximum allowable exposure levels will eliminate the risk of disease that can AUTHORIZED PERSONNEL ONLY result from inhaling non-asbestos dust. RESPIRATORS AND PROTECTIVE CLOTHING Therefore, wear respiratory protection at all times during brake servicing, beginning with the ARE REQUIRED IN THIS AREA. removal of the wheels. Wear a respirator equipped with a high-ef ciency (HEP A) lter 2. Respiratory Protection. Wear a respirator equipped with a high-ef ciency (HEP A) lter approved by NIOSH or MSHA, if the exposure levels may exceed OSHA or manufacturers’ approved by NIOSH or MSHA for use with asbestos at all times when servicing brakes, beginning recommended maximum levels. Even when exposures are expected to be within the maximum with the removal of the wheels. allowable levels, wearing such a respirator at all times during brake servicing will help minimize 3. Procedures for Servicing Brakes. exposure. a. Enclose the brake assembly within a negative pressure enclosure. The enclosure should be 3. Procedures for Servicing Brakes. equipped with a HEPA vacuum and worker arm sleeves. With the enclosure in place, use the a. Enclose the brake assembly within a negative pressure enclosure. The enclosure should be HEPA vacuum to loosen and vacuum residue from the brake parts. equipped with a HEPA vacuum and