Oil Pump: Service and Repair

OIL PUMP









1. Disassemble the oil pump using the following procedure:
a. Remove the drive spacer from the oil pump housing.
b. Remove the two screws holding the pump housing halves together.
c. Remove the inner (drive) and the outer (driven) rotors from the housing. Mark the mating surfaces. The inner rotor will have a dimple while the outer rotor has a chamfered edge.
d. Remove the oil pressure relief valve as follows:
^ Remove the pressure relief valve cap retaining pin.
^ Remove the retaining plug without damaging the O-ring seal.
^ Slide the pressure relief valve spring and piston out of its bore.
e. Clean the oil pump components in solvent.

CAUTION: The internal parts of the oil pump are not serviced separately. If wear or damage is noted, replace the entire pump assembly.

2. Inspect the oil pump components for the following conditions:
^ The housing and the cover for cracks, scoring, casting imperfections, and damaged threads.
^ The rotor gears for chipping, galling or wear.
^ Pressure relief valve piston for embedded particles and/or damage.
^ Pressure relief valve bore for scoring and smooth piston movement.
3. Assemble the oil pump using the following procedure:
a. Install the inner and the outer rotors in the pump cover in the same orientation as removed.
b. Install the pressure relief piston, spring and retaining cap in the pump housing bore.
c. Install the pressure relief valve cap retaining pin.
d. Pack the pump housing with white petroleum jelly to ensure pump priming.
e. Assemble the housing and cover over the locating dowel.
f. Insert a 3/8 inch (9.5 mm) drill in the pump mounting hole on the opposite side in order to aid in the alignment of the housing and cover.
g. Install the two retaining screws. Tighten the screws to 12 Nm (106 inch lbs.).