GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 39400-A Halogen Leak Detector

Removal Procedure


    Object Number: 1376527  Size: SH
  1. Remove the HVAC module. Refer to HVAC Module Assembly Replacement .
  2. Remove the TXV joint bracket screws (3) and remove the bracket (2) from the HVAC unit (1).
  3. Remove the heater core. Refer to Heater Core Replacement .

  4. Object Number: 1377466  Size: SH
  5. Disconnect the vacuum line (12) from the recirculation/intake actuator (11).

  6. Object Number: 1377581  Size: SH
  7. Remove the vacuum lines (5) and retainers (2) from the front HVAC module case (4).
  8. Remove the defroster actuator vacuum line.
  9. Remove the defroster actuator rod from the lever.
  10. Remove the defroster actuator retaining screws.
  11. Remove the defroster actuator (1)

  12. Object Number: 1377587  Size: SH
  13. Remove the screws attaching the front HVAC module case to the upper HVAC module case and lower HVAC module case assembly.
  14. Separate the front HVAC module case from the upper HVAC module case and lower HVAC module case assembly.

  15. Object Number: 1377584  Size: SH
  16. Remove the screws (3,5) attaching the upper HVAC module (1) to the lower HVAC module (6).
  17. Remove the clips (4) attaching the upper HVAC module case to the lower HVAC module case.
  18. Separate the upper HVAC module case from the lower HVAC module case.
  19. Remove the evaporator core (2) from the upper HVAC module case.

  20. Object Number: 1377155  Size: SH
  21. Remove the retaining screw (2) from the evaporator core pipes (4).
  22. Remove the evaporator core pipes from the evaporator core (3).
  23. Remove and discard the O-rings (1).

Installation Procedure


    Object Number: 1377155  Size: SH
  1. If installing a new evaporator core, add the specified amount of PAG. Refer to Refrigerant System Capacities .
  2. Install a new O-rings (1) to the evaporator core (3).
  3. Install the evaporator core pipes (4) to the evaporator core.
  4. 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.

  5. Secure the evaporator core pipes with the retaining screw (2).
  6. Tighten
    Tighten the screw to 5 N·m (44 lb in).


    Object Number: 1377584  Size: SH
  7. Install the evaporator core (2) to the upper HVAC module case (1).
  8. Align and install the upper HVAC module case to the lower HVAC module case (6)
  9. Install the clips (4) attaching the upper HVAC module case to the lower HVAC module case.
  10. Install the upper HVAC module case to the lower HVAC module case retaining screws (3).
  11. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).


    Object Number: 1377587  Size: SH
  12. Align and install the front HVAC module case to the upper HVAC module case and lower HVAC module case assembly.
  13. Install the front HVAC module case to the upper HVAC module case and lower HVAC module case assembly retaining screws.
  14. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).


    Object Number: 1377581  Size: SH
  15. Install the defroster actuator (1) to the HVAC module assembly.
  16. Secure the defroster actuator with the retaining screws.
  17. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).

  18. Install the defroster actuator rod to the lever.
  19. Install the defroster actuator vacuum line.
  20. Secure the retainers (2) and vacuum lines (5) to the front HVAC module case (4).

  21. Object Number: 1377466  Size: SH
  22. Connect the vacuum line (12) to the intake actuator (11).

  23. Object Number: 1376527  Size: SH
  24. Install the heater core. Refer to Heater Core Replacement .
  25. Install the TXV joint bracket (2) to the HVAC unit (1).
  26. Secure the bracket with the retaining screws (3).
  27. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).

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