Section 42 - Automatic Lubrication System 04/10 OM4207 42-4 SYSTEM COMPONENTS Filter Solenoid Valve A filter assembly mounted on the grease reservoir fil- ters the grease from the shop supply. A bypass indica- tor alerts service personnel when the filter requires replacement. Solenoid valve (5), when energized, allows oil to flow to the hydraulic motor. Flow Control Valve Hydraulic Motor and Pump Flow control valve (10) mounted on the manifold, con- trols the amount of oil flow to the hydraulic motor. The flow control valve has been factory adjusted. DO NOT attempt to adjust the setting. Hydraulic motor (3, Figure 42-1) and pump (9) together are a fully hydraulic grease pump.
An integrated pump control manifold is incorporated with the motor to con- trol input flow and pressure. NOTE: The pump crankcase oil level must be maintained to the level of the pipe plug port. Later models are equipped with a dipstick (3, 42-6). Refill with 10W-30 motor oil. Vent Valve Vent valve (7, Figure 42-1) opens and closes to control the pressure in the system. With the valve closed, the pump continues to operate until maximum grease pres- sure is achieved. As this occurs, the vent valve opens and allows the grease pressure to drop to 0, so the injectors can recharge for their next output cycle. Hydraulic oil supply inlet pressure must not exceed 20 685 kPa (3000 psi).
Exceeding the rated pressure may result in damage to system compo- nents and personal injury. Injectors Each injector (Figure 42-2) delivers a controlled amount of pressurized lubricant to a designated lube point. Grease Reservoir Grease reservoir (12) has an approximate capacity of 41 kg (90 lb) of grease. When the grease supply is replenished, grease entering the system passes through the filter to remove contaminants before set- tling into the reservoir. Lubrication Timer Lubrication timer (1, Figure 42-3) is a solid state con- troller providing a 24 VDC timed-interval signal to ener- gize solenoid valve (5, Figure 42-1).
Operation of the solenoid valve controls the oil flow to operate the hydraulic motor. This controller is mounted in the elec- trical compartment in the rear of the cab. Pressure Reducing Valve Pressure reducing valve (4), located on the manifold, reduces the hydraulic supply pressure from the truck steering circuit. Hydraulic pressure is reduced to an operating pressure of 2240 to 2415 kPa (325 to 350 psi). The hydraulic motor operates at this pressure to drive the grease pump. The pressure reducing valve has been factory adjusted. DO NOT attempt to adjust the setting. Pressure Gauge Pressure gauge (8, Figure 42-1) monitors hydraulic oil pressure to the inlet of the hydraulic motor. NOTE:
Newer models do not come equipped with a pressure gauge. However, a gauge may be installed in the port if desired.