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 21867-16 Oil Pressure Adapter
- J 21867 Pressure Gage
- J 42907 Oil Pressure Testing Tool





1. Important: This test is performed to verify the operation of the oil pressure relief valve. Refer to Displacement on Demand (DoD) System Description and Lubrication Description (Main Pressure Below 65 psi - DoD Off) Lubrication Description (Main Pressure Above 65 psi - DoD Off) Lubrication Description (Main Pressure Below 65 psi - DoD On) Lubrication Description (Main Pressure Above 65 psi - DoD On).

Remove the oil filter and install the J 42907 (1).
2. Install J 21867 (2) or equivalent to the J 42907 (1).





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





4. Install J 21867 (1) or equivalent to the J-21867-16.
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 448 kPa (65 psi), both gages should display the same pressure reading. If the readings are not the same and the lower pressure gage (2) has a higher reading, the 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 448 kPa (65 psi), the upper gage (1) should display no greater than 448 kPa (65 psi). If the reading on the upper pressure gage (1) is greater than 448 kPa (65 psi), the oil pressure relief valve is stuck in the closed position.
6. Repair as required.