OM4015.2 10/98 Lubrication & Service - Section 4 Lincoln Automatic Lubrication System Page 4-15 TROUBLESHOOTING CHART POSSIBLE CAUSES SUGGESTED CORRECTIVE ACTION TROUBLE: Pump Does Not Operate. Low air pressure. Adjust air pressure to 60 – 65 psi (414 – 448 kPa), if necessary [90 psi (621 kPa) during cold weather]. Lube system not grounded. Correct grounding connections to pump assembly and truck chassis. Electrical power loss. Locate cause of power loss and repair. 24 VDC power required; be sure keyswitch is "ON". Timer malfunction. Replace timer assembly Solenoid valve malfunctioning. Replace the solenoid valve assembly Pump malfunction. Replace pump assembly NOTE:
On intial startup of the lube system, the timing capacitor will not contain a charge, therefore the first timing cycle will be about double in length compared to the normal interval. Subsequent timer cycles should be as specified . TROUBLE: Pump Will Not Prime Low lubricant supply. Check lubricant level in reservoir and service reservoir with specified grease until grease weeps from vent plug. Dirt in reservoir, pump inlet clogged. Clean reservoir completely, remove and clean pump assembly thoroughly. Air trapped in pump. Open vent plug counterclockwise with pump running. When grease flows freely from vent, close vent plug clockwise. NOTE:
System air applied to the lube system air pump is also applied to the vent valve. When the pump is operating, air pressure keeps the vent valve closed and grease is directed from the pump outlet and to the injectors. When air supply to the air motor is interrupted, the vent valve opens and supply pressure vents back to the reservoir . Safety unloader valve faulty. Replace safety unloader valve. NOTE: The safety unloader valve prevents buildup of excessively high pressure in the lube system which could damage components. This valve is factory preset to open between 3750 - 4250 psi (25.9 - 29.3 MPa). The valve is not serviceable, nor is it adjustable. Outlet check valve clogged.
Remove check valve from pump outlet, clean thor- oughly or replace.