Section 42 - Automatic Lubrication System 04/10 OM4207 42-8 LUBRICANT PUMP Pump Housing Oil Level The pump housing must be filled to the proper level with SAE 10W-30 motor oil. Check the oil level at 1000 hour intervals. To add oil, remove plug (4, Figure 42-6) and fill the housing to the bottom of the plug hole. Newer models are equipped with a dipstick (3). Remove the dipstick and add oil to the proper level. Pump Pressure Control High pressure hydraulic fluid from the truck steering system is reduced to 2240 to 2413 kPa (325 to 350 psi) by pressure reducing valve (1). The reducing valve is located on the manifold on top of the pump motor.
Operating pressure can be read on the gauge installed on the manifold. Occasionally check the gauge to verify pressure is within the specified range. The pressure reducing valve is not adjustable. If operating pressure is not within limits, the pressure reducing valve must be replaced. FIGURE 42-6. PUMP CONTROLS 1. Pressure Reducing Valve 2. Test Switch 3. Dipstick 4. Oil Level Plug 5. Flow Control Valve