Section 4 - Maintenance OM4033.2 4-20 Automatic Lubrication System LUBRICANT PUMP Pump Housing Oil Level The pump housing must be filled to the proper level with SAE 10W-30 motor oil. Oil level should be checked at 1000 hour intervals. To add oil, remove pipe plug (4, Figure 4-6) and fill housing to bottom of plug hole. Pump Pressure Control High pressure hydraulic fluid from the truck steering system is reduced to 325 to 350 psi (2 240 to 2 413 kPa) by the pressure reducing valve located on the manifold on top of the pump motor. This pressure can be read on the gauge installed on the manifold and should be checked occasionally to verify pressure is within the above limits.
Pressure Control Valve Adjustment 1. With the truck engine running, activate the lube system manual test switch (2, Figure 4-6) to start the hydraulic motor and pump. FIGURE 4-6. PUMP CONTROLS 2. Loosen the locknut on the pressure control (1, Figure 4-6) by turning the nut counterclockwise. 1. Pump Pressure Control 2. Test Switch 3. Pressure Gauge 4. Oil Level Plug 5. Flow Control Valve 3. Turn the valve stem counterclockwise until it no longer turns. (The valve stem will unscrew until it reaches the stop - it will not come off.) Note: This is the minimum pressure setting, which is about 170 psi (1 172 kPa). 4.
With the pump stalled against pressure, turn the pressure control valve stem clockwise until 325 to 350 psi (2 240 to 2 413 kPa) is attained on the manifold pressure gauge (2). 5. Tighten the locknut to lock the stem in position. Note: The flow control valve (5) is factory adjusted to 2.5 GPM (9.5 L/min.). Do not change this setting.