Kysor On/Off Diagnostic Guide

bwthermal.com Technology you can count on 1. Air pressure must be checked at drive. A known source of dry and filtered air is rec- ommended for all tests. CONDITION 2. Refer to appropriate service manual for rebuild and repair instructions. 3. Proper precautions must be taken to prevent personal injury from contact with moving TEST parts, unintended engine start or other hazards present when working with powered equipment. Refer to the vehicle owners manual and/or appropriate service manual ACTION for proper safety precautions before beginning any diagnostic or repair procedures.

Clutch operating correctly, Kysor fan drives Repair Vehicle air are spring vehicle pressure engaged and control present air released. system. Clutch Liner is Repair Will Not worn any drive damage Engage caused Vehicle air Housing Test for by faulty Check liner movement proper pressure wear control. NOT present operation Apply & Liner is release not worn 90-110 psi Remove clutch of air. & inspect for internal No housing damage movement

1 Fan rotates freely Drive is ok

Apply 90-110 psi Housing Remove clutch movement of air pressure. Fan does not & inspect for Repair Rotate fan. rotate freely internal vehicle Vehicle air Apply & damage control pressure release system. present pressure Repair Clutch Apply Housing Test for any drive No housing 90-110 psi movement proper damage Will Not movement of air & tap operation caused housing with by faulty Disengage soft hammer. control. Remove clutch No housing & inspect for movement internal damage Vehicle air pressure 2NOT present Inspect pulley and clutch. Coupler is Repair or rounded out replace if bearing damage is found.

Remove clutch Air Leak & inspect plastic In Drive coupler Repair or replace Piston rod or pulley hub. rear O-ring seal Inspect & repair Inspect is damaged. clutch as piston rod necessary. Coupler is near O-ring not damaged seal Inspect pulley hub. Repair No piston rod clutch with damage seal kit or seal 3 & liner kit. Rounded Out blued along with other surfaces and components. The front face Coupler Damage of the clutch may have dark The coupler is located streaks radiating outwards from between the rear of the fan the access hole area. (Figure 5) clutch and the pulley hub These deposits are caused by center shaft. It is made of an overheated lining. Dark dusty Figure 5 Dark streaks from overheating semi-hard black plastic, deposits on the inside of the 13/8” diameter x 5/8” clutch housing also indicate overheating. thick, with a flat sided hole Control problems causing excessive cycling or low air pressure Figure 1 Pulley hub with coupler in through the center. (Figure 1) are the most common causes of clutch overheating and lining fail- place on shaft ure. Mechanical obstructions to the clutch or fan will also cause There is no load on the coupler lining slippage and overheating. during clutch operation. The Correct any fan clutch control system defects that cause over coupler simply keeps the clutch cycling and slippage of the clutch. Extensive overheating may piston rod (center shaft) from cause damage to the clutch bearings, seals and other internal turning. It couples the piston components. In this case it is advisable to replace the clutch rod to the shaft of the pulley rather than repair it with a kit. hub by engaging both the flats of piston rod and the pulley hub shaft. The O-ring on the Fan Clutch Piston rear of the piston rod is the air Figure 2 Clutch with rear O-ring A on piston rod Rod Damage seal between the clutch and Damage to the rear of the piston pulley hub. (Figure 2) rod (center shaft) and rear O-ring Rounded out damage to the coupler and rear O-ring failure can is usually caused by worn or dam- occur when the clutch piston rod is forced to rotate. (Figure 3-2) aged pulley hub bearings. This This can be caused may first be noticed as an air leak by a clutch bearing at the rear of the clutch. failure or improper The rear portion of the piston rod clutch servicing. enters into the front of the pulley The clutch cylinder Figure 3 hub shaft. Bearing wear or dam- B 1 - Good coupler cap must be held age in the pulley hub may cause 2 2 - Rounded out coupler stationary by hand 1 3 - Melted couplers the pulley to not run true on the when removing the shaft. Bearing wear can cause front retainer nut. damage to the rear O-ring and If the coupler is eventually the piston rod. (Figure 3 rounded out, the 6) There should be no play in the clutch ball bearings pulley hub bearings. Check for need to be inspected carefully. The clutch should be replaced if scuffed plating on the piston rod bearings are damaged or worn. around the O-ring area. Check C Always replace the coupler and rear O-ring when servicing the for worn metal at the rear of the clutch or hub. piston rod. If the metal is not damaged, the clutch can be reused. Overheated Fan Clutch (Melted Coupler) Always determine and correct the cause of failure. Inspect and make An overheated fan clutch can be recog- any pulley hub repairs or replace nized by the bluing effect (discoloration) the pulley hub as required if worn present on the rear of the clutch. (Figure or damaged. Pulley hub bearing 4) The bluing effect will appear on the kits are available for service. Figure 6 O-ring area of new piston rod surface of the clutch that mounts against (Figure A), minor damage at rear of piston the pulley. The shape of the front face of rod showing scuffed plating serviceable with the pulley may appear on the back of the repair kit (Figure B), and severe damage to rear Figure 4 Bluing effect clutch as a lighter steel color. The raised of piston rod showing worn-away metal, not pilot on the back of the clutch may also be serviceable. (Figure C) bwthermal.com

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