Opel Corsa B 1993–2000 Service and Repair Manual: Oil pump - removal and refitting

Removal

1. Remove the sump.

2. Undo the two socket-headed bolts and withdraw the pump from the crankcase (see illustrations).

Undo the two socket-headed bolts (arrowed) . . .

. . . and remove the oil pump

Refitting

3. Refitting the pump is the reverse sequence to removal, but engage the pump shaft in the distributor driveshaft slot, and tighten the retaining bolts to the specified torque.

Oil pump - overhaul

1. Remove the oil pump.

2. Undo the two pump cover bolts and lift off the cover and oil pick-up tube. Remove the cover gasket.

3. Take out the driving gear and driven gear (see illustrations).

Removing the oil pump driving gear . . .

. . . and the driven gear

4. Undo the large nut on the side of the housing and remove the sealing washer and oil pressure relief spring and ball valve (see illustration).

Oil pump and pressure relief valve components

5. Clean all the parts in paraffin and dry with a lint-free cloth.

6. Inspect the pump gears, housing, cover and relief valve ball for scoring, scuff marks or other signs of wear and renew the pump if these signs are evident.

7. If the pump condition is satisfactory, check the pump clearances as follows.

8. Using a feeler blade, check the backlash between the gear teeth. Place a straight-edge across the top edge of the gears and check their projection. If any of the clearances exceeds the tolerances given in the Specifications, renew the pump (see illustration).

Check the pump gear teeth backlash

9. If the clearances are satisfactory, refit the relief valve assembly and assemble the pump gears. Fill the pump with oil and refit the cover using a new gasket. Tighten the cover securing bolts and refit the pump.