Displacement on Demand (Dod) Oil Pressure Relief Valve Diagnosis and Testing

Displacement on Demand (DoD) Oil Pressure Relief Valve Diagnosis and Testing

^ Tools Required
^ J 21867 Pressure Gage
^ J-21867-16 Oil Pressure Adapter
^ J 42907 Oil Pressure Tester





1. Important: This test is performed to verify the operation of the displacement on demand (DoD) oil pressure relief valve. Refer to Displacement on Demand (DoD) System Description and Lubrication Description (Main Pressure Below 55 psi - DoD Off) Lubrication Description (Main Pressure Above 55 psi - DoD Off) Lubrication Description (Main Pressure Below 55 psi - DoD On) Lubrication Description (Main Pressure Above 55 psi - DoD On).

Remove the oil filter and install the J 42907.
2. Install the J 21867 or equivalent to the J 42907.





3. Remove the oil pressure sensor and install the J-21867-16.





4. Install the J 21867 (1), or equivalent, to the J-21867-16 (2).
5. Run the engine and measure the engine oil pressure while observing both gages. Operate the throttle as required to increase and decrease the engine oil pressure.
^ With the engine running and the lower pressure gage (2) measuring below 379 kPa (55 psi), both gages should display the same pressure reading. If the readings are not the same and the lower gage (2) has a higher reading, the DoD oil pressure relief valve is stuck in the open position or the valve lifter oil manifold filter is plugged.
^ With the engine running and the lower pressure gage (2) measuring above 379 kPa (55 psi), the upper gage (1) should display no greater than 379 - 517 kPa (55 - 75 psi). If the reading on the upper gage (1) is greater than 517 kPa (75 psi), the DoD oil pressure relief valve is stuck in the closed position.
6. Repair as required.