GM Service Manual Online
For 1990-2009 cars only

Special Tools

J 39400-A Halogen Leak Detector

Removal Procedure

  1. Recover the refrigerant. Refer to Refrigerant Recovery and Recharging .
  2. Drain the coolant. Refer to Cooling System Draining and Filling .
  3. Disconnect the heater inlet hose from the heater core. Refer to Heater Inlet Hose Replacement .
  4. Disconnect the heater outlet hose from the heater core. Refer to Heater Outlet Hose Replacement .
  5. At the evaporator core, disconnect and remove the A/C quick connect fittings from the suction hose and the liquid line. Refer to Air Conditioning Line/Tube Connector Removal/Replacement .
  6. Separate the suction hose and liquid line from the evaporator core.
  7. Remove and discard the O-rings.

  8. Object Number: 756222  Size: SH
  9. Remove the instrument panel (I/P) carrier. Refer to Instrument Panel Carrier Replacement .
  10. Remove the blower and air inlet assembly.
  11. Disconnect the HVAC module electrical connector.
  12. Disconnect the HVAC module drain tube (2) from the floor.

  13. Object Number: 756232  Size: SH
  14. Remove the lower left HVAC module mounting nut (1).

  15. Object Number: 756237  Size: SH
  16. Remove the upper left HVAC module mounting nut (1).
  17. Remove the HVAC module from the vehicle.

  18. Object Number: 817511  Size: SH
  19. Remove the foam from the A/C lines.
  20. Remove the foam from around the heater pipes.

Installation Procedure


    Object Number: 819805  Size: SH
  1. Install the thick foam packing (1) on the heater core pipes.
  2. Install the thin foam packing (2) on the heater core pipes.

  3. Object Number: 819804  Size: SH
  4. Install the thick foam packing (1) on the A/C lines.
  5. Install the thin foam packing (2) on the A/C lines.

  6. Object Number: 756237  Size: SH
  7. Install the HVAC module into the vehicle.
  8. Notice: Refer to Fastener Notice in the Preface section.

  9. Install the upper left HVAC module mounting nut (1).
  10. Tighten
    Tighten the nut to 9 N·m (80 lb in).


    Object Number: 756232  Size: SH
  11. Install the lower left HVAC module mounting nut (1).
  12. Tighten
    Tighten the nut to 9 N·m (80 lb in).

  13. Connect the drain tube to the bottom of the HVAC module.

  14. Object Number: 756222  Size: SH
  15. Connect the drain tube (2) to the floor.
  16. Connect the HVAC electrical connector.
  17. Install the air inlet assembly.
  18. Install the I/P carrier. Refer to Instrument Panel Carrier Replacement .
  19. Install new O-rings to the suction hose and liquid line. Refer to O-Ring Replacement .
  20. Connect the suction hose and liquid line to the evaporator core.
  21. Install the A/C quick connect fittings to the suction hose and liquid line. Refer to Air Conditioning Line/Tube Connector Removal/Replacement .
  22. Connect the heater inlet hose to the heater core. Refer to Heater Inlet Hose Replacement .
  23. Connect the heater outlet hose to the heater core. Refer to Heater Outlet Hose Replacement .
  24. Fill the coolant. Refer to Cooling System Draining and Filling .
  25. Evacuate and recharge the AC system. Refer to Refrigerant Recovery and Recharging .
  26. Leak test the fittings of the component using J 39400-A .