For 1990-2009 cars

1. Remove the O-ring seal from the water pump.
2. Inspect the O-ring seal for damage.

Replace the seal if damaged.

3. Clean the water pump with a non-corrosive solvent.
4. Inspect the water pump for the following:

• | Gasket sealing surfaces for excessive scratches or gouging

• | Restrictions within the internal coolant passages

• | Excessive side-to-side play in the pulley shaft

5. Coat the O-ring seal with silicone grease, GM P/N 12345579, or equivalent.
6. Install the O-ring seal to the water pump.