To determine if a defective pressure relief valve is causing low oil pressure, perform the following steps:
1.2.Remove the pressure relief valve; refer to appropriate service manual, lubrication system chapter.
Inspect the oil pressure relief valve; refer to appropriate service manual, lubrication system chapter.
[a] If the relief valve moves freely in the valve body, reinstall the oil pressure relief
valve; refer to appropriate service manual, lubrication system chapter. Check the
pickup tube and screen assembly for defects, refer to section 2.10.
[b] If the relief valve will not move freely in the valve body, refer to section 2.9.1.
2.9.1
Pressure Relief Valve Repair
Perform the following steps to repair the pressure relief valve:
1. Disassemble the pressure relief valve and replace damaged components; refer to appropriate service manual, lubrication system chapter.
2. Assemble and install the pressure regulator valve; refer to appropriate service manual, lubrication system chapter.
3. Verify repair of the regulator valve; refer to section 2.9.1.1.
2.9.1.1
Test Engine with Repaired Relief Valve
Perform the following steps to determine if repaired relief valve resolved low oil pressure:
1. Connect to DDDL 7.0.
2. Start and run 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), or more 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, check pickup tube and screen assembly; refer to section 2.10.
