GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 Chevy P12 Chassis 🢒 Engine 🢒 Engine Mechanical - 7.4L 🢒 Water Pump Replacement

Removal Procedure

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  1. Disconnect the negative battery cable.
  2. Drain the cooling system. Refer to Cooling System Draining and Filling .
  3. Remove the radiator upper shroud section. Refer to Fan Shroud Replacement .
  4. Remove the serpentine drive belt. Refer to Drive Belt Replacement .
  5. Remove the fan clutch. Refer to Fan Clutch Replacement .
  6. Remove the lower radiator hose from the pump.

    7. Object Number: 48325 Size: SH
  7. Disconnect the coolant bypass hose from the pump.
  8. Remove the coolant pump retaining bolts.
  9. Remove the coolant pump.
  10. Clean the gasket sealing surfaces on the coolant pump and on the engine block.

Installation Procedure

    Object Number: 48325 Size: SH
  1. Install new gaskets to the block mating surface.

    2. 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.

  2. Install the coolant pump and retaining bolts to the engine block.

    3. Tighten
    Tighten the coolant pump retaining bolts to 41 N·m (30 lb ft).

  3. Install the bypass hose and clamps.
  4. Install the lower radiator hose and clamp.
  5. Install the fan clutch. Refer to Fan Clutch Replacement .
  6. Install the serpentine drive belt. Refer to Drive Belt Replacement .
  7. Install the upper radiator shroud. Refer to Fan Shroud Replacement .
  8. Fill the cooling system. Refer to Cooling System Draining and Filling .
  9. Start the engine. Allow the engine to run with the surge tank cap removed until the radiator upper hose is hot and the thermostat is open.
  10. While the engine is idling, add coolant to the surge tank until the coolant level reaches the full mark.
  11. Install the surge tank cap.

    12. Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  12. Connect the negative battery cable.