GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 39400-A Halogen Leak Detector

Removal Procedure

  1. Remove HVAC module. Refer to HVAC Module Assembly Replacement .

  2. Object Number: 933678  Size: SH
  3. Remove TXV to backing plate attachment bolts and remove TXV and backing plate.
  4. Remove O-rings from evaporator pipes and caps to prevent system contamination.
  5. Remove HVAC module front of dash seal.

  6. Object Number: 933065  Size: SH
  7. Remove heater duct.

  8. Object Number: 932987  Size: SH
  9. Disconnect HVAC module harness from all three mode actuators.
  10. Remove panel, defrost and floor mode actuators. If blower case assembly is being replaced, mode actuators do not need to be removed.

  11. Object Number: 933022  Size: SH
  12. Remove heater core cover.

  13. Object Number: 932938  Size: SH
  14. Remove heater core pipe cover.
  15. Remove heater core pipe seal.

  16. Object Number: 932945  Size: SH
  17. Grasp heater core at end tanks and remove. Spraying perimeter of heater core seal with a soap and water mixture will ease removal.

  18. Object Number: 932965  Size: SH
  19. Remove evaporator cover assembly.

  20. Object Number: 932990  Size: SH
  21. Remove evaporator pipe retainer.

  22. Object Number: 932971  Size: SH
  23. Remove evaporator. Spraying perimeter of evaporator core seal with a soap and water mixture will ease removal.

Installation Procedure


    Object Number: 932971  Size: SH
  1. Inspect seal around evaporator. Make sure seal is in correct position and retained properly.
  2. Spray seal with a soap and water mixture to ease the installation of evaporator.
  3. Install evaporator.

  4. Object Number: 932965  Size: SH
  5. Install evaporator cover assembly.
  6. 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.

  7. Install evaporator cover assembly screws.
  8. Tighten
    Tighten the screws to 1 N·m (9 lb in).


    Object Number: 932990  Size: SH
  9. Install evaporator pipe retainer.
  10. Install evaporator pipe retainer screws.
  11. Tighten
    Tighten the screws to 1 N·m (9 lb in).


    Object Number: 932957  Size: SH
  12. Install heater core. Spraying perimeter of heater core seal with a soap and water mixture will ease installation.
  13. Install heater core pipe seal.

  14. Object Number: 932938  Size: SH
  15. Install heater core pipe cover.
  16. Install heater core pipe cover screws.
  17. Tighten
    Tighten the screws to 1 N·m (9 lb in).


    Object Number: 933022  Size: SH
  18. Install heater core cover.
  19. Install heater core cover screws.
  20. Tighten
    Tighten the screws to 1 N·m (9 lb in).


    Object Number: 932987  Size: SH
  21. Install panel, defrost and floor mode actuators.
  22. Install actuator screws.
  23. Tighten
    Tighten the screws to 1 N·m (9 lb in).


    Object Number: 933065  Size: SH
  24. Install heater duct.
  25. Install heater duct screws.
  26. Tighten
    Tighten the screws to 1 N·m (9 lb in).


    Object Number: 933678  Size: SH
  27. Install HVAC module front of dash seal. Inspect and if damaged, replace.
  28. Important: Use only R-12 refrigerant oil (mineral) to lubricate O-rings. Use of R-134a PAG oil will cause premature corrosion of fitting joints.

    Use only clean lint free cloths with non-petroleum based solvents to clean refrigerant system sealing surfaces. Allow solvent to dry with air. Do not allow solvents to enter refrigerant system.

  29. Remove evaporator pipe caps and insure seal areas are clean, dry and lint free.
  30. Install new O-rings to evaporator lubricating with mineral oil. Refer to O-Ring Replacement .
  31. Remove shipping caps and install TXV to evaporator pipes with backing plate and bolts.
  32. Tighten
    Tighten the bolts to 9 N·m (80 lb in).

  33. Install the HVAC module. Refer to HVAC Module Assembly Replacement .