GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 38185 Hose Clamp Pliers

Removal Procedure

  1. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  2. Remove the wiper module. Refer to Windshield Wiper System Module Replacement in Wipers/Washer Systems.
  3. Disconnect the brake booster vacuum hose and reposition.
  4. Remove the air cleaner cover and intake tube. Refer to Air Cleaner Inlet Duct Replacement in Engine Controls - 3.4 L.
  5. Important: Disconnect the throttle and cruise control cables from the TBI mounting bracket to prevent bending the cable housings.

  6. Disconnect the throttle and cruise control cables.
  7. Remove the transmission fluid filler tube. Refer to Transmission Fluid Filler Tube Replacement in Automatic Transaxle.
  8. Disconnect both heater hose quick disconnects from the inlet and outlet pipes.

  9. Object Number: 819323  Size: SH
  10. Disconnect both of the heater hose clamps from the heater hoses using the J 38185 .
  11. Remove the heater hoses from the heater core.
  12. Important: Cap off the heater core inlet and outlet pipes to prevent coolant spillage inside of the vehicle.

  13. Cap off the heater core pipes.
  14. Remove the right instrument panel insulator. Refer to Instrument Panel Insulator Panel Replacement - Right Side in Instrument Panel, Gages and Console.
  15. Remove the left instrument panel insulator. Refer to Instrument Panel Insulator Panel Replacement - Left Side in Instrument Panel, Gages and Console.
  16. Remove the center floor air outlet. Refer to Floor Air Outlet Replacement - Center .

  17. Object Number: 825398  Size: SH
  18. Remove the screws retaining the heater outlet duct.
  19. Remove the heater outlet duct.
  20. Remove the IP harness to heater core cover tie strap.

  21. Object Number: 825396  Size: SH
  22. Remove the screws retaining the heater core cover.
  23. Remove the heater core cover.

  24. Object Number: 825397  Size: SH
  25. Remove the heater core pipe retaining clamp screw.
  26. Remove the heater core from the HVAC module.

Installation Procedure

  1. Install the heater core to the HVAC module case.
  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.


    Object Number: 825397  Size: SH
  3. Install the heater core pipe retaining clamp screw.
  4. Tighten
    Tighten the screw to 0.9 N·m (8 lb in).


    Object Number: 825396  Size: SH
  5. Install the heater core cover.
  6. Install the heater core cover retaining screws.
  7. Tighten
    Tighten the screws to 0.9 N·m (8 lb in).


    Object Number: 825398  Size: SH
  8. Install the heater outlet duct.
  9. Install the heater outlet duct screws.
  10. Tighten
    Tighten the screws to 0.9 N·m (8 lb in).

  11. Install the IP harness to heater core cover tie strap.
  12. Install the center floor air outlet. Refer to Floor Air Outlet Replacement - Center .
  13. Install the left instrument panel insulator. Refer to Instrument Panel Insulator Panel Replacement - Left Side in Instrument Panel, Gages and Console.
  14. Install the right instrument panel insulator. Refer to Instrument Panel Insulator Panel Replacement - Right Side in Instrument Panel, Gages and Console.

  15. Object Number: 819323  Size: SH
  16. Install the heater hoses to the heater core.
  17. Connect the heater hose clamps using the J 38185 .
  18. Connect the heater hose quick connects to the inlet and outlet pipes.
  19. Install the transmission fluid filler tube. Refer to Air Cleaner Inlet Duct Replacement in Automatic Transaxle.
  20. Install the air cleaner cover and intake hose. Refer to Air Cleaner Inlet Duct Replacement in Engine Controls - 3.4 L.
  21. Connect the throttle and cruise control cables to the TBI mounting bracket.
  22. Connect the brake booster vacuum hose.
  23. Install the wiper module. Refer to Windshield Wiper System Module Replacement in Wipers/Washer Systems.
  24. Fill the coolant. Refer to Cooling System Draining and Filling in Engine Cooling.