GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 38185 Hose Clamp Pliers

Removal Procedure

  1. Remove the following component:
  2. • For a 3.1L engine, remove the air cleaner assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls-3.1L.
    • For a 3.8L engine, remove the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement in Engine Mechanical-3.8L.
  3. Remove the cross vehicle brace. Refer to Cross Vehicle Brace Replacement in Body Front End.
  4. Drain the coolant. Refer to Cooling System Draining and Filling in Engine Cooling.

  5. Object Number: 414213  Size: SH
  6. UseJ 38185 in order to position aside the heater hose inlet and outlet clamp at the heater core.
  7. Disconnect the inlet and outlet heater hose from the heater core.
  8. Remove the floor carpet. Refer to Front Floor Panel Carpet Replacement in Interior Trim.
  9. Remove the rear floor air outlet duct from the holes in the floor reinforcement.
  10. Disconnect the rear floor air outlet duct from the heater core outlet cover.
  11. Remove the bolts from the vacccum harness bracket and position bracket aside.

  12. Object Number: 508311  Size: SH

    Important: Position the heater core outlet cover downward and rearward in order to disconnect the cover from the rear area floor duct assembly.

  13. Remove the screws from the heater core outlet cover.
  14. Remove the heater core outlet cover.

  15. Object Number: 295349  Size: SH
  16. Remove the screws from the heater core cover.
  17. Remove the heater core cover.

  18. Object Number: 143978  Size: SH
  19. Remove and discard the seals (1,2) from the heater core cover.
  20. Remove the caulk (3) from the heater core cover.

  21. Object Number: 296242  Size: SH
  22. Remove and discard the outer seal (5) from the heater core.

  23. Object Number: 295351  Size: SH
  24. Remove the screw (1) from the heater core line clamp.
  25. Remove the heater core retaining clamp.
  26. Remove the screw (2) from the heater core pipe retainer clamp.

  27. Object Number: 295353  Size: SH
  28. Remove the heater core from the HVAC lower case.

  29. Object Number: 143987  Size: SH
  30. Remove and discard the lower seal (4) from the HVAC case.

  31. Object Number: 143992  Size: SH
  32. Remove and discard the center seal (3) from the HVAC case.

  33. Object Number: 143985  Size: SH
  34. Remove and discard the upper seal (2) from the HVAC lower case.

  35. Object Number: 143990  Size: SH
  36. Remove and discard the side seals (1) from the HVAC lower case.

Installation Procedure


    Object Number: 143990  Size: SH
  1. Install the side seals (1) to the HVAC lower case.

  2. Object Number: 143985  Size: SH
  3. Install the upper seal (2) to the HVAC lower case.

  4. Object Number: 143992  Size: SH
  5. Install the center seal (3) to the HVAC case.

  6. Object Number: 143987  Size: SH
  7. Install the lower seal (4) to the HVAC case.

  8. Object Number: 295353  Size: SH
  9. Install the heater core to the HVAC lower case.

  10. Object Number: 295351  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.

  11. Install the screw (2) to the heater core line clamp.
  12. Tighten
    Tighten the screw to 1.5 N·m (13 lb in).

  13. Install the screw (1) to the heater core mounting clip.
  14. Tighten
    Tighten the screw to 1.5 N·m (13 lb in)


    Object Number: 296242  Size: SH
  15. Install outer seal (5) to the heater core.

  16. Object Number: 143978  Size: SH
  17. Install new seals(1,2) to the heater core cover.
  18. Install the caulk (3) on to the heater core cover.

  19. Object Number: 295349  Size: SH
  20. Install the heater core cover.
  21. Install the heater core cover screws.
  22. Tighten
    Tighten the screws to 1.5 N·m (13 lb in).


    Object Number: 508311  Size: SH
  23. Install the heater core outlet cover.
  24. Install the screws to the heater core outlet cover.
  25. Tighten
    Tighten the screws to 1.5 N·m (13 lb in).

  26. Install the HVAC vaccum harness bracket.
  27. Install the bolts to the HVAC vaccum harness bracket.
  28. Tighten
    Tighten the screws to 1.5 N·m (13 lb in).

  29. Connect the rear floor air outlet duct to the heater core outlet cover.
  30. Install the rear floor air outlet duct to the holes in the floor reinforcement.
  31. Install the floor carpet. Refer to Front Floor Panel Carpet Replacement in Interior Trim.

  32. Object Number: 414213  Size: SH
  33. Connect the inlet and outlet heater hose to the heater core.
  34. Important: Reposition the heater core hose clamps in the indicated location.

  35. UseJ 38185 in order to reposition the heater hose inlet and outlet clamp to the heater core.
  36. Fill the coolant. Refer to Cooling System Draining and Filling in Engine Cooling.
  37. Install the cross vehicl brace. Refer to Cross Vehicle Brace Replacement in Body Front End.
  38. Install the following component:
  39. • For a 3.1L engine, install the air cleaner assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls - 3.1L.
    • For a 3.8L engine, install the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement in Engine Mechanical - 3.8L.