MBE 4000 DDEC VI Troubleshooting – Section 15.8 Defective Oil Pump Pressure Relief Valve

Section 15.8
Defective Oil Pump Pressure Relief Valve

To determine if a defective oil pump pressure relief valve is causing low oil pressure, perform the following steps:‪

1. Remove the oil pump pressure relief valve.
2. Inspect the oil pump pressure relief valve.
   1. If the relief valve moves freely in the valve body, reinstall the oil pressure relief valve. Check the suction pipe for defects.
   2. If the relief valve will not move freely in the valve body, refer to "15.8.1 Oil Pump Pressure Relief Valve Repair" .

Section 15.8.1
Oil Pump Pressure Relief Valve Repair

Perform the following steps to repair the oil pump pressure relief valve:‪

1. Disassemble the pressure relief valve and replace damaged components.
2. Assemble and install the pressure relief valve.
3. Verify repair of the pressure relief valve; refer to "15.8.1.1 Test Engine with Repaired Oil Pump Pressure Relief Valve" .

Section 15.8.1.1
Test Engine with Repaired Oil Pump Pressure Relief Valve

Perform the following steps to determine if repaired oil pump pressure relief valve resolved low oil pressure:‪

1. Install the DDR.

   PERSONAL INJURY ‪
   To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked.‪

2. Start and run engine speed at rated speed.
3. Visually examine the DDR for oil pressure reading.
   1. If the DDR indicates 241 kPa (35 psi) or more at rated speed, shut down the engine and disconnect the DDR. No further troubleshooting is required.
   2. If the DDR indicates less than 241 kPa (35 psi) at rated speed, shut down the engine and disconnect the DDR. Check for defective suction pipe; refer to "15.9 Defective Suction Pipe" .