GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 Blazer - 4WD - RHD 🢒 Engine 🢒 Engine Cooling 🢒 Water Pump Replacement

Removal Procedure
  1. Drain the coolant from the radiator. Refer to Cooling System Draining and Filling .
  2. Remove the drive belt. Refer to Drive Belt Replacement in Engine Mechanical-4.3L.
  3. Remove the upper fan shroud. Refer to Fan Shroud Replacement .
  4. Remove the cooling fan and clutch assembly. Refer to Fan Clutch Replacement .

    5. Object Number: 42879 Size: SH
  5. Remove the water pump drive pulley mounting bolts.
  6. Remove the water pump pulley.
  7. Remove upper radiator hose from the water pump.

    8. Object Number: 42880 Size: SH
  8. Remove the water pump mounting bolts.

    9. Object Number: 42882 Size: SH
  9. Remove the water pump from the engine.

    10. Object Number: 42884 Size: SH
  10. Remove the water pump gaskets.
  11. Ensure that all mating surfaces are clean and free of gasket material or burrs.

Installation Procedure

    Object Number: 42884 Size: SH
  1. Install the water pump gaskets.

    2. Object Number: 42882 Size: SH
  2. Install the water pump to the engine.
  3. Apply a sealer, GM P/N 12346004, to the bolt threads.

    4. Object Number: 42880 Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  4. Install the water pump mounting bolts.

    5. Tighten
    Tighten the mounting bolts to 41 N·m (30 lb ft).

  5. Place the radiator outlet hose clamp loosely on the end of the hose.
  6. Install the upper radiator hose.

    7. Object Number: 42879 Size: SH
  7. Install the water pump drive pulley.
  8. Install the fan clutch assembly. Refer to Fan Clutch Replacement .
  9. Install the drive belt. Refer to Drive Belt Replacement in Engine Mechanical-4.3L.
  10. Install the upper fan shroud. Refer to Fan Shroud Replacement .
  11. Fill the radiator with the specified coolant and concentration. Refer to Cooling System Draining and Filling .
  12. Inspect the cooling system for leaks.