Oil Pump Service

1. Remove pressure relief valve as follows:
a. Remove cotter pin.
b. Drill a 1/8 inch hole into relief valve retainer cap and insert a self threading sheet metal screw.
c. Clamp screw into vise and while supporting oil pump remove cap by tapping pump body with soft faced hammer.
d. Discard retainer cap, then remove spring and relief valve.
2. Remove oil pump cover.
3. Remove pump outer and inner rotor with shaft, then wash all parts in solvent.

INSPECTION

1. Inspect oil pump cover. Replace if scratched or grooved.
2. Position a straightedge across pump cover surface. If a 0.0015 inch feeler gauge can be inserted between cover and straightedge, replace assembly.
3. Measure thickness and diameter of outer rotor. Replace if thickness is 0.825 inch or less, or diameter is 2.469 inches or less.
4. Replace inner rotor and shaft assembly if inner rotor is 0.825 inch or less thick.
5. Slide outer rotor into pump body. Press rotor to side and measure clearance between rotor and pump body. Replace assembly if clearance is 0.014 inch or less.
6. Install inner rotor and shaft into pump body. Replace shaft and both rotors if clearance between inner and outer rotors is 0.008 inch or more.
7. Place a straightedge across face of pump between bolt holes. Replace pump assembly if a feeler gauge of 0.004 inch or more can be inserted between rotors and straightedge.
8. Inspect oil pressure relief valve plunger for scoring and free operation in its bore.
9. Ensure relief valve spring has a free length of approximately 1.95 inches.
10. Relief valve spring should test between 19.5-20.5 lbs. when compressed to 1.34375 inches.

ASSEMBLE

1. Install pump rotors and shaft.
2. Position oil pump cover onto pump body. Tighten cover bolts to specification.
3. Install relief valve and spring, then insert cotter pin.
4. Tap on new retainer cap.
5. Prime oil pump before installing.