OM4207 04/10 Automatic Lubrication System - Section 42 42-13 SYSTEM TROUBLESHOOTING CHART NOTE: I f the following procedures do not correct the problem, contact a factory authorized service center. Symptom Possible Causes Corrective Action Pump Does Not Operate Lube system not grounded. Electrical power loss. Controller malfunction. Solenoid valve malfunctioning. Motor or pump malfunction. Correct grounding connections to pump assem- bly and truck chassis. Locate cause of power loss and repair. 24 VDC power required. Ensure key switch is ON. Replace the controller assembly Replace the solenoid valve assembly Repair or replace motor and/or pump assembly.
Refer to the service manual for rebuild instruc- tions. Pump Will Not Prime Low lubricant supply. Dirt in reservoir, pump inlet clogged, filter clogged. Pump Will Not Build Pressure Air trapped in lubricant supply line. Lubricant supply line leaking. Vent valve leaking. Pump worn or scored. Prime system to remove trapped air. Check lines and connections to repair leakage. Clean or replace vent valve. Repair or replace pump assembly. Refer to the service manual for rebuild instructions. Injector Indicator Stem Does Not Operate NOTE: Normally during operation, the injector indicator stem will move into the body of the injector when pressure builds.
When the system vents and releases pressure, the indicator stem will again move out into the adjusting yoke. Malfunctioning injector - usually indi- cated by the pump building pressure and then venting. All injectors inoperative - pump build up not sufficient to cycle injectors. Replace individual injector assembly. Service and/or replace pump assembly. Refer to the service manual for rebuild instructions. Pressure Gauge Does Not Register Pressure No system pressure to the pump motor. No 24 VDC signal at pump solenoid. Pressure reducing valve not functioning properly. Check hydraulic hose from steering system. Determine problem in 24 VDC electric system. Refer to Pump Pressure Control.