GM Service Manual Online
For 1990-2009 cars only

Air Conditioning (A/C) Coupling Assembly Replacement High Pressure

Special Tools

J 39400-A Halogen Leak Detector

Removal Procedure

  1. Recover the refrigerant from the A/C system. Refer to Refrigerant Recovery and Recharging.
  2. Remove the right wheelhouse panel. Refer to Wheelhouse Panel Replacement.

  3. Object Number: 798587  Size: SH
  4. Remove the A/C coupling (2, 3) from the evaporator hose (4).

  5. Object Number: 798589  Size: SH
  6. Remove the sealing valve (1) from the A/C coupling (2).

  7. Object Number: 798588  Size: SH
  8. Remove the sealing valve (1) from the A/C coupling (2).

Installation Procedure

  1. Coat the new sealing valves with PAG oil.

  2. Object Number: 798588  Size: SH
  3. Install the sealing valve (1) to the A/C coupling (2).

  4. Object Number: 798589  Size: SH
  5. Install the sealing valve (1) to the A/C coupling (2).
  6. Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 798587  Size: SH
  7. Install the A/C coupling (2, 3) to the evaporator hose (4).
  8. Tighten
    Tighten the fittings to 35 N·m (26 lb ft).

  9. Install the right wheelhouse panel. Refer to Wheelhouse Panel Replacement.
  10. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging.
  11. Leak test the fittings of the components using the J 39400-A .

Air Conditioning (A/C) Coupling Assembly Replacement Low Pressure

Special Tools

J 39400-A Halogen Leak Detector

Removal Procedure

  1. Recover the refrigerant from the A/C system. Refer to Refrigerant Recovery and Recharging.
  2. Remove the air cleaner. Refer to the appropriate procedure:
  3. •  Air Cleaner Assembly Replacement for the 6.6L engine
    •  Air Cleaner Replacement for the 8.1L engine
    •  Air Cleaner Replacement for the 7.8L engine
    •  Air Cleaner Replacement for the 7.2L (Caterpillar) engine
  4. Remove the right wheelhouse panel. Refer to Wheelhouse Panel Replacement.
  5. Remove the evaporator outlet tube. Refer to Air Conditioning Evaporator Hose Assembly Replacement.

  6. Object Number: 816816  Size: SH
  7. Remove the air conditioning (A/C) coupling (2, 4) from the evaporator tube (1, 3).

  8. Object Number: 798589  Size: SH
  9. Remove the sealing valve (1) from the A/C coupling (2).

  10. Object Number: 798588  Size: SH
  11. Remove the sealing valve (1) from the A/C coupling (2).

Installation Procedure

  1. Coat the new sealing valves with polyalkylene glycol (PAG) oil.

  2. Object Number: 798588  Size: SH
  3. Install the sealing valve (1) to the A/C coupling (2).

  4. Object Number: 798589  Size: SH
  5. Install the sealing valve (1) to the A/C coupling (2).
  6. Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 816816  Size: SH
  7. Install the A/C coupling (2, 4) to the evaporator tube (1, 3).
  8. Tighten
    Tighten the fittings to 45 N·m (33 lb ft).

  9. Install the evaporator outlet tube. Refer to Air Conditioning Evaporator Hose Assembly Replacement.
  10. Install the air cleaner. Refer to the appropriate procedure:
  11. •  Air Cleaner Assembly Replacement for the 6.6L engine
    •  Air Cleaner Replacement for the 8.1L engine
    •  Air Cleaner Replacement for the 7.8L engine
    •  Air Cleaner Replacement for the 7.2L (Caterpillar) engine
  12. Install the right wheelhouse panel. Refer to Wheelhouse Panel Replacement.
  13. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging.
  14. Leak test the fittings of the components using the J 39400-A .