Oil Pump: Service and Repair

Oil Pump And Oil Pressure Relief Valve

NOTE: Overhaul procedures for the oil pump and oil pressure relief valve are limited to carrying out dimensional checks. In the event of wear or damage being found, a replacement timing cover and oil pump assembly must be fitted.

Oil pump - remove
1. Remove timing cover.

CAUTION: Do not attempt to remove oil pump drive gear from inner rotor at this stage.







2. Remove 7 screws and bolt securing oil pump cover plate, remove plate.







3. Make suitable alignment marks on inner and outer rotors, remove rotors and oil pump drive gear as an assembly.

Oil pressure relief valve - remove







1. Remove circlip.
2. Remove relief valve plug, remove and discard O ring.
3. Remove relief valve spring and piston.

Oil Pump - Inspection
1. Thoroughly clean oil pump drive gear, cover plate, rotors and housing. Remove all traces of Loctite from cover plate securing screws; ensure tapped holes in timing cover are clean and free from oil.
2. Check mating surfaces of cover plate, rotors and housing for scoring.
3. Assemble rotors and oil pump drive gear in housing ensuring that reference marks are aligned.







4. Using feeler gauges, check clearance between teeth of inner and outer rotors:
Maximum clearance = 0.25 mm (0.01 in)







5. Remove oil pump drive gear, check depth of any wear steps on gear teeth:
Wear step maximum depth = 0.15 in (0.006 in)







6. Place a straight edge across housing.
7. Using feeler gauges, check clearance between straight edge and rotors:
Maximum clearance = 0.1 mm (0.004 in).

Oil Pressure Relief Valve - Inspection
1. Clean relief valve components and piston bore in timing cover.
2. Check piston and bore for scoring and that piston slides freely in bore with no perceptible side movement.
3. Check relief valve spring for damage and distortion; check spring free length: Spring free length = 60.0 mm (2.4 in).

Oil Pump - Refit
1. Lubricate rotors, oil pump drive gear, cover plate and housing with engine oil.
2. Assemble rotors and drive gear in housing ensuring that reference marks are aligned.
3. Position cover plate to housing.
4. Apply Loctite 222 to threads of cover plate screws and bolt.
5. Fit cover plate screws and bolt and tighten to:-
Screws - 4 Nm (3 ft. lbs.)
Bolt - 8 Nm (6 ft. lbs.)

6. Fit timing cover.

Oil Pressure Relief Valve - Refit
1. Lubricate new 'O' ring with engine oil and fit to relief valve plug.
2. Lubricate relief valve spring, piston and piston bore with engine oil.
3. Assemble piston to relief valve spring, insert piston and spring into piston bore.
4. Fit relief valve plug, depress plug and fit circlip.
5. Ensure circlip is fully seated in groove.