Cleaning and Inspection Procedure - Required

Courtesy of GENERAL MOTORS COMPANY

Clean the oil pump (1) sealing surfaces with solvent.
Dry the oil pump (1) sealing surfaces.
Inspect the oil pump (1) sealing surfaces.
Remove all gasket and sealing material using the EN-28410 Gasket Remover or equivalent.
Courtesy of GENERAL MOTORS COMPANY

NOTE:
Do not remove the pickup tube.

Inspect the oil pan (1) for the following conditions:
1. Damaged oil pan gasket and sealing surfaces
2. Restrictions within the oil passages of the pan
3. Damaged oil filter seal surface
Courtesy of GENERAL MOTORS COMPANY

Clean all excess dirt and debris from the water pump (1).
Inspect the water pump (1) for the following conditions:
1. Water pump gasket and hose sealing surfaces for excessive scratches or gouging
2. Restrictions within the internal coolant passages
3. Excessive side-to-side play in the pulley shaft
4. Leakage at the water inlet housing or rear cover
5. Leakage at the water outlet housing or water pump outlet
6. Leakage at the water pump vent hole
  A stain around the vent hole is acceptable. If leakage or dripping occurs with the engine running and the cooling system pressurized, replace the water pump (1).
7. Wear or damage in the belt tracking area of the water pump pulley