Inspection & Repair Procedure

2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Inspection & Repair Procedure
WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Remove the O-ring from the water pump.
  2. Remove the water pump to water pump housing bolts.
  3. Remove the water pump from the water pump housing.
  4. Remove the O-ring from the water pump housing.
  5. Clean the water pump assembly.
  6. Clean the water pump mating surfaces.
  7. Inspect the water pump gear for damage.
  8. Inspect the water pump mating surfaces for damage.
  9. Inspect the water pump shaft for looseness.
  10. Inspect the water pump assembly for damage.
  11. Replace the water pump if any damage is found.
  12. Install a new O-ring to the water pump housing.
  13. Lubricate the O-ring with engine coolant.
  14. Install the water pump to the water pump housing.
  15. Install the water pump to water pump housing bolts. Tighten the water pump to water pump housing bolts to 21 N.m (15 lb ft).
  16. Install a new O-ring to the water pump.
RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.