GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 39400-A Halogen Leak Detector

Removal Procedure

  1. Recover the refrigerant. Refer to Refrigerant Recovery and Recharging .
  2. Remove the cross vehicle brace. Refer to Cross Vehicle Brace Replacement in Body Front End.
  3. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  4. Remove the cross vehicle beam. Refer to Instrument Panel Tie Bar Replacement in Instrument Panel, Gauges and Console.
  5. Remove the A/C lines from the evaporator block fitting. Refer to Evaporator Tube Replacement .
  6. Remove the heater hoses from the heater core. Refer to Heater Hoses Replacement .

  7. 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.

  8. Remove the heater core outlet cover screws.
  9. Remove the heater core outlet cover.

  10. Object Number: 282300  Size: SH
  11. Remove the evaporator blower motor clog tube.

  12. Object Number: 507700  Size: SH
  13. Remove the HVAC module assembly mounting nuts from the cowl.
  14. Disconnect the vacuum hoses.
  15. Disconnect the electrical connectors.
  16. Remove the HVAC module assembly.

  17. Object Number: 283719  Size: SH
  18. Remove all of the outer HVAC module assembly seals (1, 2, 3).

Installation Procedure


    Object Number: 283719  Size: SH
  1. Install new outer HVAC module assembly seals (1, 2, 3).
  2. Install the HVAC module assembly to the vehicle.

  3. Object Number: 507700  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 HVAC module assembly to dash nuts.
  5. Tighten
    Tighten the HVAC module assembly nuts to 10 N·m (89 lb in).


    Object Number: 282300  Size: SH
  6. Install the evaporator blower motor clog tube.
  7. Connect the electrical connectors.
  8. Connect the vacuum hoses.

  9. Object Number: 508311  Size: SH
  10. Install the heater core outlet cover.
  11. Install the heater core outlet cover screws.
  12. Tighten
    Tighten the heater core outlet cover screws to 1.5 N·m (13 lb in).

  13. Install the cross vehicle beam. Refer to Instrument Panel Tie Bar Replacement in Instrument Panel, Gauges and Console.
  14. Install the heater hoses to the heater core. Refer to Heater Hoses Replacement in Engine Cooling.
  15. Install the A/C lines to the evaporator block fitting. Refer to Evaporator Tube Replacement .
  16. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  17. Install the cross vehicle brace. Refer to Cross Vehicle Brace Replacement in Body Front End.
  18. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging .
  19. Leak test the fittings of the component using J 39400-A .