Maintenance - Section 4 Rotary Pump OM4026.2 4/00 Page 4-22 Automatic Lubrication System SYSTEM CHECKOUT To check system operation (not including timer), pro- ceed as follows: 1. Turn keyswitch “ON” and start the engine. 2. Actuate the Lube System Test Switch at the reservoir/pump assembly on the front bumper. 3. The motor and pump should operate until the system attains 2500 psi (17 237 kPa). 4. Once the required pressure is achieved, the pump motor should turn off and the system should vent. 5. Check for pump, hose or injector damage or leakage with the system under pressure. FIGURE 4-9. TIMER (TOP COVER REMOVED) 6.
After checking system, shutdown engine, observ- ing normal precautions regarding high voltage present in the propulsion system before attempt- ing to repair lube system. 1. Timer Enclosure 2. Red LED (Light Emitting Diode) 3. Timer Selector LUBRICATION CYCLE TIMER CHECK To check the solid state timer operation without waiting for the normal timer setting, proceed as follows: Lubrication Cycle Timer Adjustment 1. Remove timer dust cover. NOTE: The timer incorporates a liquid and dust tight cover which must be in place and secured at all times during truck operation . The timer is factory set for a nominal 2.5 minute (off time) interval. Dwell time is approximately 1 minute, 15 seconds.
A longer interval (off time) is obtained by turning the Selector knob (3, Figure 4-9) to the desired position . 2. Adjust timer selector (3, Figure 4-9) to 5 minute interval setting. NOTE: Set timer by turning the Selector knob (3) to the 2.5 minute setting point. Then, turn the Selector clock- wise, one detent at a time, to the desired setting, or until the maximum limit of eighty minutes is reached . 3. The timer should cycle in five minutes if the truck is operating. NOTE: If the timer check is being made on a cold start, the first cycle will be approximately double the nominal setting. All subsequent cycles should be within the selected time tolerance .
The timer is a sealed unit, do not attempt disas- sembly. 4. Voltage checks at the timer should be accom- plished if the above checks do not identify the problem. a. Insure timer ground connection is clean and tight. b. Using a Volt-Ohm meter, read the voltage between positive and negative posts on the solid state timer with the truck keyswitch “ON”. Normal reading should be 18-26 VDC, depend- ing upon whether or not the engine is running.