Section 2.9
Defective Pressure Relief Valve

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

1. Remove the pressure relief valve; refer to appropriate service manual, lubrication system chapter.
2. Inspect the oil pressure relief valve; refer to appropriate service manual, lubrication system chapter.
   1. 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 "2.10 Defective Pickup Screen Tube and Screen Assembly" .
   2. If the relief valve will not move freely in the valve body, refer to "2.9.1 Pressure Relief Valve Repair" .

Section 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 "2.9.1.1 Test Engine with Repaired Relief Valve" .

Section 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.
   1. 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.
   2. 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 "2.10 Defective Pickup Screen Tube and Screen Assembly" .