Oil Pump: Testing and Inspection

NOTE:
Internal components are not serviced separately. If any component is out of specification, replace the complete oil pump.

Refer to Specifications for clearances and service limits.

1. Check the inside of the pump housing, the outer race and rotor for damage or excessive wear.
2. Check the mating surface of the oil pump cover for wear. Although minor scuff marks are normal, replace the oil pump if the cover mating surface is worn, scored or grooved.
3. Inspect the rotor for nicks, burrs or score marks. Remove minor imperfections with an oil stone.





NOTE: With rotor assembly removed from the oil pump and resting on a flat surface, the inner and outer rotor tip clearance must not exceed 0.06-0.18 mm (0.0024-0.0071 inch) with feeler gauge inserted 13 mm (0.5 inch) minimum.

4. Measure the inner rotor tip clearance.





5. With the rotor assembly installed in the housing, place Straight Edge D83L-4201-A or equivalent over the rotor assembly and the housing.
6. Measure the clearance (rotor end play) between straight edge and the rotor and outer race. Maximum clearance must not exceed 0.03-0.09 mm (0.0012-0.0035 inch).
7. Inspect the relief valve spring to see if it is collapsed or worn. Check the relief valve spring tension. If the spring tension is not within specification and/or the spring is worn or damaged, replace the oil pump.
8. Check the relief valve piston for free operation in the bore.