Oil Pump Inspection Inspect the rotor and shaft of the oil pump for excessive wear and garring. Check the condition of the seal on the shaft, the o-rings, and clean up the pressure relief spring.
I have found that using an impact and 12mm socket is good to remove the pump sprocket. With the sprocket Removed, the shaft will slide out. The seal can be replaced now.
Replace the seal and reinstall the sprocket, with an impact, do this with the pump off (or do it with the pump filly assembled and on the car, to prime the oil system) There is an o-ring around the base of the pump, and a â€œmickey mouseâ€ shaped o-ring that goes against the mating surface.
The rotor can go either on the pump or in the motor, with the letter â€œBâ€ facing the motor Make sure the o-rings are lined up, and that the oil pump seats against the motor flush. The sprocket should turn freely. Snug the 5 bolts down, middle, left, then right until you know the pump is flush, turns freely, then torque down. Use a Â¼â€ drive socket so you don’t over torque and break the bolts!
be sure to prime the pump! if it runs dry you run a chance of it breaking!
composed with help from mile’s fox’s site at http://www.economysuperstar.com/milesfox/subaru/subaru.htm