Water Pump Cleaning and Inspection

WARNING: This page is about a different car, the 2003 GMC Envoy XL and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

Remove the old gasket from the water pump sealing surfaces. Refer to REPLACING ENGINE GASKETS .
Clean all excess dirt and debris from the water pump housing.
Inspect the water pump for the following:
- Gasket and hose sealing surfaces for excessive scratches or gouging
- Restrictions within the internal coolant passages
- Excessive side-to-side play in the pulley shaft
- Leakage at the water outlet housing or rear cover gasket
- Leakage at the water pump vent hole
  A stain around the vent hole is acceptable. If leakage, dripping, occurs with the engine running and the cooling system pressurized, replace the water pump.
  
  Fig 1: Inspecting Water Pump
  Courtesy of GENERAL MOTORS CORP.
Inspect the water pump pulley for wear or damage in the belt tracking area.

Fig 2: Inspecting Water Pump Pulley For Wear Or Damage In Belt Tracking Area
Courtesy of GENERAL MOTORS CORP.