Oil Pump: Service and Repair

Oil Pump Replacement

Tools Required
^ J35268-A Camshaft/Front Main Seal Installer

1. Remove the oil pump pipe and screen assembly.
2. Remove the crankshaft drive gear.
3. Remove the engine oil pressure switch.





4. Remove the generator lower mounting bolt (2).
5. Loosen the generator upper mounting bolt (1).
6. Pivot the generator out of the way and tighten the generator upper mounting bolt only enough to hold in position.





7. Remove the oil pump bolts.
8. Remove the oil pump and gasket.
9. Remove the front main oil seal from the oil pump.
10. Clean the engine block and oil pan sealing surfaces.
11. Clean and inspect the oil pump.
12. Disassemble the oil pump if necessary.

Installation Procedure
1. Assemble the oil pump if necessary.






Important: Do not cover and/or restrict the gasket openings and oil passages with sealant. Only apply sealant to the crosshatched area of the gasket as shown in the illustration.

2. Coat only the pump side of the new oil pump gasket with a thin, even coating of GM P/N 1052942 (Canadian P/N 10953466), or equivalent.
3. Install the oil pump gasket.





4. Position the oil pump to the engine block (1) while aligning the guide pins (2).
5. Coat the oil pump bolts with GM P/N 12345382 (Canadian P/N 10953489), or equivalent.






Important: The oil pump bolts must be re-tightened AFTER the generator mounting bolt has been tightened to specifications to allow for uniform compression of the oil pump gasket.

6. Install the oil pump bolts.

Tighten the oil pump bolts in sequence to 12 Nm (106 inch lbs.).





Important: Ensure the crankshaft front oil seal is fully and evenly seated.

7. Tap the crankshaft front oil seal into place using the J35268-A.





8. Release and pivot the generator into place.
9. Install the generator lower mounting bolt (2).

Tighten the generator mounting bolts to 35 Nm (26 ft. lbs.).

Important: The oil pump bolts must be re-tightened AFTER the generator mounting bolt has been tightened to specifications to allow for uniform compression of the oil pump gasket.

Re-tighten the oil pump bolts.

10. Tighten the oil pump bolts in sequence to 28 Nm (21 ft. lbs.).
11. Install the engine oil pressure switch.
12. Install the crankshaft drive gear.
13. Install the oil pump pipe and screen assembly.