Oil Pump: Testing and Inspection

Cleaning
Wash all parts in a solvent and dry them thoroughly with compressed air. Use a brush to clean the inside of the oil pump housing and the pressure relief valve chamber. Remove all dirt and metal particles.

Inspection

NOTE: Internal components cannot be serviced. If any component is out of specification, replace the complete oil pump.





The inner rotor tip-to-outer rotor tip clearance must not exceed 0.06-0.18 mm (0.0024-0.0071 inch) with Feeler Gauge Set 303-D027 (D81L-4201-A) or equivalent inserted 12.7 mm (1/2 inch) minimum and rotors removed from the pump housing.





With the rotor assembly installed in the pump housing, place a Straight Edge 303-D039 (D83L-4201-A) or equivalent over the rotor assembly and housing. Measure the clearance (rotor end play) between the Straight Edge 303-D039 (D83L-4201-A) or equivalent and the rotor, and outer race. The clearance should be 0.0-0.09 mm (0.0012-0.0035 inch).
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 or the spring is worn or damaged, replace the oil pump. Check the relief valve piston for free operation in the bore.