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

Tools Required

J 39400-A Halogen Leak Detector

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 in Body Front End.



3. Remove the A/C coupling (2, 3) from the evaporator hose (4).



4. Remove the sealing valve (1) from the A/C coupling (2).



5. Remove the sealing valve (1) from the A/C coupling (2).

1. Coat the new sealing valves with PAG oil.



2. Install the sealing valve (1) to the A/C coupling (2).



3. Install the sealing valve (1) to the A/C coupling (2).

Notice: Refer to Fastener Notice in the Preface section.




4. Install the A/C coupling (2, 3) to the evaporator hose (4).

Tighten
Tighten the fittings to 35 N·m (26 lb ft).

5. Install the right wheelhouse panel. Refer to Wheelhouse Panel Replacement in Body Front End.
6. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging .
7. Leak test the fittings of the components using the J 39400-A .

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

Tools Required

J 39400-A Halogen Leak Detector

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:

•	Air Cleaner Replacement in Engine Controls - 7.2L (Caterpillar)

•	Air Cleaner Replacement in Engine Controls - 8.1L

•	Air Cleaner Replacement in Engine Controls - 7.8L

•	Air Cleaner Replacement

•	Caterpillar® 3126 Unit Repair Manual

3. Remove the right wheelhouse panel. Refer to Wheelhouse Panel Replacement in Body Front End.
4. Remove the evaporator outlet tube. Refer to Air Conditioning Evaporator Hose Assembly Replacement .



5. Remove the A/C coupling (2, 4) from the evaporator tube (1, 3).



6. Remove the sealing valve (1) from the A/C coupling (2).



7. Remove the sealing valve (1) from the A/C coupling (2).

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



2. Install the sealing valve (1) to the A/C coupling (2).



3. Install the sealing valve (1) to the A/C coupling (2).

Notice: Refer to Fastener Notice in the Preface section.




4. Install the A/C coupling (2, 4) to the evaporator tube (1, 3).

Tighten
Tighten the fittings to 45 N·m (33 lb ft).

5. Install the evaporator outlet tube. Refer to Air Conditioning Evaporator Hose Assembly Replacement .
6. Install the air cleaner. Refer to the appropriate procedure:

•	Air Cleaner Replacement in Engine Controls - 7.2L (Caterpillar)

•	Air Cleaner Replacement in Engine Controls - 8.1L

•	Air Cleaner Replacement in Engine Controls - 7.8L

•	Air Cleaner Replacement Caterpillar® 3126 Unit Repair Manual

7. Install the right wheelhouse panel. Refer to Wheelhouse Panel Replacement in Body Front End.
8. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging .
9. Leak test the fittings of the components using the J 39400-A .