Section 42 - Automatic Lubrication System 04/10 OM4207 42-6 SYSTEM OPERATION 1. During truck operation, the lubrication controller 5. During this period, the injectors will meter the will energize the system at a preset time interval. appropriate amount of grease to each lubrication point. 2. The controller provides 24 VDC to energize the pump solenoid valve. The solenoid controls the 6. When the timing period is complete, the controller hydraulic oil provided by the steering circuit. The will remove the power from the pump solenoid hydraulic oil drives the motor and pump. valve. 3. Hydraulic oil pressure from the steering circuit is 7.
After the pump solenoid is de-energized, hydrau- reduced to 2240 to 2413 kPa (325 to 350 psi) by lic pressure in the manifold drops and vent valve pressure reducing valve (4, Figure 42-5) before (11) will open. When the vent valve opens, grease entering the motor. The amount of oil supplied to pressure in the lines is released to the injector the pump is limited by flow control valve (6). banks. When this occurs, the injectors are then Pump pressure can be read using gauge (5) able to recharge for the next lubrication cycle. mounted on the manifold. 8. The system will remain at rest until the lubrication 4.
With oil flowing into the hydraulic motor, the controller turns on and initiates a new grease grease pump suctions grease from the reservoir. cycle. Grease output from the pump flows through check valve (10) to injectors (13) and to vent valve (11). FIGURE 42-5. HYDRAULIC SCHEMATIC 1. Hydraulic Oil Return 6. Flow Control Valve 11. Vent Valve 2. Hydraulic Oil Supply 7. Hydraulic Motor 12. Orifice 3. Pump Solenoid Valve 8. Grease Pump 13. Injector Bank 4. Pressure Reducing Valve 9. Pressure Switch (Optional) 5. Motor Pressure Gauge 10. Check Valve