Measure the tip clearance of rotors. If the clearance is out of specification, replace the rotors as a set.
Tip clearance:
Specification
0.04 — 0.14 mm (0.0016 — 0.0055 in)
Measure the clearance between the outer rotor and the oil pump case. If clearance is out of standard, replace the oil pump case.
Case clearance:
Specification
0.10 — 0.175 mm (0.0039 — 0.0069 in)
Measure the clearance between the oil pump inner rotor and the oil pump cover by checking the step between the inner rotor and the oil pump cover as shown in the following figure. If the clearance is out of specification, replace the rotors and the oil pump case.
Side clearance:
Specification
0.02 — 0.07 mm (0.0008 — 0.0028 in)
Check the valve for assembly condition and damage, and the relief valve spring for damage and deterioration. Replace the parts if defective.
Relief valve spring:
Free length
73.7 mm (2.902 in)
Installed length
54.7 mm (2.154 in)
Load when installed
93.1 N (9.49 kgf, 20.93 lbf)
Check the oil pump case for worn shaft hole, clogged oil passage, worn rotor chamber, cracks and other faults.
Check the front oil seal lips for deformation, hardening, wear, etc.