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.
[a] If the drive gear rotates freely in the pump housing, call the Detroit Diesel Customer
Support Center 313–592–5800.
[b] If the drive gear did not rotate freely; refer to section 2.12.1.
2.12.1
Oil Pump Assembly Repair
Perform the following steps to repair the oil pump assembly:
1. Disassemble the oil pump assembly and replace worn or damaged components as required; refer to appropriate service manual, lubrication system chapter.
2. Reassemble the oil pump; refer to appropriate service manual, lubrication system chapter.
3. Verify oil pump repair; refer to section 2.12.1.1.
2.12.1.1
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.
[a] 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.
[b] 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).
