Section 2.12
Defective Oil Pump Assembly

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

1. Remove the oil pump assembly; refer to appropriate service manual, lubrication system chapter.
2. Manually rotate the oil pump drive gear.
   1. If the drive gear rotates freely in the pump housing, call the Detroit Diesel Customer Support Center 313–592–5800.
   2. If the drive gear did not rotate freely; go to the next step.
3. Disassemble the oil pump assembly and replace worn or damaged components as required; refer to appropriate service manual, lubrication system chapter.
4. Reassemble the oil pump; refer to appropriate service manual, lubrication system chapter.
5. Verify oil pump repair; refer to "2.12.1 Test Engine with Repaired Oil Pump Assembly" .

Section 2.12.1
Test Engine with Repaired Oil Pump Assembly

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

1. Connect to DDDL 7.0.
2. Start and run the engine speed at 1800 rpm.
3. Visually examine DDDL 7.0 for oil pressure reading.
   1. If DDDL 7.0 indicates 241 kPa (35 psi) at 1800 rpm, shut down the engine and disconnect DDDL 7.0. No further troubleshooting is required.
   2. If DDDL 7.0 indicates less than 241 kPa (35 psi) at 1800 rpm, shut down the engine and disconnect DDDL 7.0; call the Detroit Diesel Customer Support Center (313–592–5800).