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. Caution: Refer to Fastener Caution 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 .