GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 39400-A Halogen Leak Detector

Removal Procedure

  1. Remove the HVAC module. Refer to HVAC Module Assembly Replacement .
  2. Disconnect the vacuum harness from both of the harness retainers on the HVAC module case.

  3. Object Number: 295305  Size: SH
  4. Disconnect the vacuum harness connectors from the defroster actuator.
  5. Rotate the defrost door lever fully rearward (counterclockwise), then carefully insert a flat bladed tool between the bottom of the defrost door lever and the protruding wall of the HVAC module case below the door lever in order to keep the door lever in place.

  6. Object Number: 295306  Size: SH
  7. Lift to release the defroster actuator retaining tab.

  8. Object Number: 295308  Size: SH
  9. Disconnect the defroster actuator pushrod from the defrost door lever and remove the actuator.

  10. Object Number: 295357  Size: SH
  11. Remove the screws retaining the HVAC module case - upper to the HVAC module case - lower.
  12. To access the screw hidden under the air inlet door, open the door and retain in the open position.

  13. Release the retaining tab (1) securing the HVAC module case - upper to the HVAC module case - lower.
  14. Separate the HVAC module case - upper from the HVAC module case - lower.

  15. Object Number: 296249  Size: SH
  16. Remove and discard the HVAC module case seals.
  17. Start to remove the HVAC module case primary (blower motor side of case) seal (2) from the HVAC module case - lower at the position shown (1).


    Object Number: 295362  Size: SH
  18. Remove the evaporator core from the HVAC module case - lower.

Installation Procedure


    Object Number: 628096  Size: SH
  1. If installing a new evaporator core, add the specified amount of PAG Refer to Refrigerant System Capacities .

  2. Object Number: 144102  Size: SH
  3. Install a new water core filter to the evaporator core.

  4. Object Number: 144106  Size: SH
  5. Install a new side seal to the evaporator core.
  6. Line the evaporator core side seal up with the corners of the evaporator core.


    Object Number: 144104  Size: SH
  7. Install a new upper seal to the evaporator core.

  8. Object Number: 144107  Size: SH
  9. Install two new lower seals to the evaporator core.
  10. Locate the seals at the outer corners (or edges) of the evaporator core.


    Object Number: 295362  Size: SH
  11. Install the evaporator core to the HVAC module case - lower.

  12. Object Number: 296253  Size: SH
  13. Install new case seals to the HVAC module case - lower.
  14. Start to install the HVAC module case primary (blower motor side of case) seal (2) to the HVAC module case - lower from the position shown (1).


    Object Number: 295357  Size: SH

    Important: Inspect the condition of the retaining tab on the HVAC module case - upper prior to installing to the HVAC module case - upper to the HVAC module case - lower. If the retaining tab is broken or damaged, install an external retaining clip.

  15. Align and install the HVAC module case - upper to the HVAC module case - lower.
  16. Align and secure the retaining tab (1) on the HVAC module case - upper to the retaining slot on the HVAC module case - lower.

    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.

  17. Install the HVAC module case - upper to the HVAC module case - lower retaining screws.
  18. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).


    Object Number: 295308  Size: SH
  19. Connect the defroster actuator pushrod to the defrost door lever.

  20. Object Number: 295306  Size: SH
  21. Position the defroster actuator in line with the mounting pins on the HVAC module case.
  22. Carefully rotate the defroster actuator until the actuator slots align with the HVAC module mounting pins.
  23. Inspect that the defroster actuator pushrod is not binding on the defrost door lever.
  24. Push the defroster actuator toward the HVAC module case to secure the retaining tab.

  25. Object Number: 295305  Size: SH
  26. Remove the flat bladed tool maintaining the defrost door lever in position.
  27. Connect both of the vacuum harness connectors to the defroster actuator.
  28. Secure the vacuum harness to both of the harness retainers on the HVAC module case.
  29. Install the HVAC module to the vehicle. Refer to HVAC Module Assembly Replacement .