Oil Pump: Testing and Inspection

INSPECTION





1. Inspect relief valve.
Coat the valve with engine oil and check that it falls smoothly into the valve hole by its own weight.
If it doesn't, replace the relief valve. If necessary, replace the oil pump assembly.
2. Inspect drive and driven rotors.





A. Inspect rotor body clearance.
Using a feeler gauge, measure the clearance between the driven rotor and body.
Standard body clearance: 0.08 - 0.18 mm (0.0031 - 0.0071 inch)
Maximum body clearance: 0.20 mm (0.0079 inch)
If the body clearance is greater than maximum, replace the rotors as a set. If necessary, replace the oil pump assembly.





B. Inspect rotor tip clearance.
Using a feeler gauge, measure the clearance between the drive and driven rotor tips.
Standard tip clearance: 0.025 - 0.085 mm (0.0010 - 0.0033 inch)
Maximum tip clearance: 0.35 mm (0.0138 inch)
If the tip clearance is greater than maximum, replace the rotors as a set.





C. Inspect rotor side clearance.
Using a thickness gauge and precision straight edge, measure the clearance between the rotors and precision straight edge.
Standard side clearance: 0.025 - 0.085 mm (0.0010 - 0.0033 inch)
Maximum side clearance: 0.10 mm (0.0039 inch)
If the side clearance is greater than maximum, replace the rotors as a set. If necessary, replace the oil pump assembly.