Inspection

(1) Wash all parts in a suitable solvent and inspect carefully for damage or wear.
(2) Mating surface of the oil pump should be smooth. Replace pump cover if scratched or grooved.





(3) Lay a straightedge across the pump cover surface. If a feeler gauge of 0.076 mm (0.003 inch) or more can be inserted between cover and straightedge, cover should be replaced.

Limit: 0.076 mm (0.003 inch)





(4) Measure thickness and diameter of outer rotor. If outer rotor thickness measures 7.64 mm (0.301 inch) or less, or if the diameter is 79.95 mm (3.148 inch) or less, replace outer rotor.





(5) If inner rotor measures limit or less' replace inner rotor.

Limit: 7.64 mm (0.301 inch)





(6) Slide outer rotor into pump housing, press to one side with fingers and measure clearance between rotor and housing. If measurement exceeds the limit, replace housing (only if outer rotor is in specification.)

Limit: 0.39 mm (0.015 inch)





(7) Install inner rotor into pump housing. If clearance between inner and outer rotors exceeds the limit, replace both rotors.

Limit: 0.203 mm (0.008 inch)





(8) Place a straightedge across the face of the pump housing, between bolt holes. If a feeler gauge of 0.102 mm (0.004 inch) or more can be inserted between rotors and the straightedge, replace pump assembly.

Limit: 0.102 mm (0.004 in)

(9) Inspect oil pressure relief valve plunger for scoring and free operation in its bore. Small marks may be removed with 400-grit wet or dry sandpaper.
(10) The relief valve spring has a free length of approximately 60.7 mm (2.39 inch). It should test between 80 and 84N when compressed to 40.5 mm (1.60 inch). Replace spring that fails to meet specifications.





(11) If oil pressure is low and pump is within specifications, inspect for worn engine bearings or other reasons for oil pressure loss.