GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 38185 Hose Clamp Pliers

Caution: With a pressurized cooling system, the coolant temperature in the radiator can be considerably higher than the boiling point of the solution at atmospheric pressure. Removal of the surge tank cap, while the cooling system is hot and under high pressure, causes the solution to boil instantaneously with explosive force. This will cause the solution to spew out over the engine, the fenders, and the person removing the cap. Serious bodily injury may result.

Removal Procedure

  1. Drain the cooling system. Refer to Cooling System Draining and Filling .
  2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .

  3. Object Number: 893494  Size: SH
  4. Place a drain pan under the water pump drain port.
  5. Loosen the water pump drain bolt and drain the coolant from the water pump.
  6. Notice: Refer to Fastener Notice in the Preface section.

  7. Close and tighten the water pump drain bolt.
  8. Tighten
    Tighten the water pump drain bolt to 10 N·m (88 lb in).

  9. Lower the vehicle.

  10. Object Number: 872578  Size: SH
  11. Reposition the heater outlet hose clamp at the heater core using J 38185 .
  12. Remove the heater outlet hose from the heater core.

  13. Object Number: 872572  Size: SH
  14. Reposition the heater inlet hose clamp at the heater core using J 38185 .
  15. Remove the heater inlet hose from the heater core.
  16. Remove the heater core cover. Refer to Heater Core Cover Replacement .

  17. Object Number: 872606  Size: SH
  18. Remove the heater core.

Installation Procedure


    Object Number: 872606  Size: SH
  1. Inspect the foam heater core seal on the lower HVAC case. If damaged, replace using Kent Industries adhesive black foam tape P/N 46480 or equivalent.
  2. Install the heater core into the HVAC module.
  3. Install the heater core cover. Refer to Heater Core Cover Replacement .

  4. Object Number: 872578  Size: SH
  5. Install the heater outlet hose to the heater core.
  6. Install the hose clamp to secure the hose using J 38185 .

  7. Object Number: 872572  Size: SH
  8. Install the heater inlet hose to the heater core.
  9. Install the hose clamp to secure the hose using J 38185 .
  10. Fill the cooling system. Refer to Cooling System Draining and Filling .