Oil Pump: Testing and Inspection

NOTE: If any part of pump requires replacement, the entire pump assembly must be replaced.

1. Inspect inside of pump housing, outer race and rotor for excessive wear or scoring.
2. Inspect mating surface of pump cover for excessive wear, or scoring. Either of these conditions will necessitate replacement of pump.

Fig. 20 Oil Pump Inner Rotor Tip Clearance Inspection:

3. Measure inner rotor tip clearance, Fig. 20.

Fig. 21 Oil Pump Rotor Endplay Measurement:

4. Measure rotor endplay, Fig. 21. Maximum endplay should be 0.004 inch.
5. Check driveshaft to housing bearing clearance. This measurement should be 0.0015-0.0030 inch.
6. Check relief valve spring tension. Spring tension should be 12.6-14.5 lbs.
7. Inspect relief valve piston for scores and free operation in bore.