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 .
3. Remove the air cleaner. Refer to the appropriate procedure:

•	Air Cleaner Replacement for the 6.6L (LBZ and LLY) engine

•	Air Cleaner Replacement for the 8.1L engine

•	Air Cleaner Replacement for the 7.8L engine

•	Caterpillar® 3126 Unit Repair Manual for the 7.2L (Caterpillar) engine

4. Disconnect the low pressure sensor electrical connector.
5. Disconnect the blower motor assembly electrical connector.
6. Disconnect the blower motor resistor assembly electrical connector.
7. Remove the multi-use module bracket. Refer to the appropriate procedure:

•	Multiuse Module Bracket Replacement for the 8.1L engine

•	Multiuse Module Bracket Replacement for the 7.8L engine

•	Caterpillar® 3126 Unit Repair Manual




8. Remove the evaporator outlet hose retaining nut (5) from the accumulator.



9. Remove the compressor inlet hose retaining nut (2).
10. Disconnect the low pressure sensor electrical connector.



11. Remove the retaining nuts (3) from the accumulator retaining bracket.
12. Remove the accumulator (5) from the bracket.
13. Remove the O-ring seals.



14. Remove the retaining nut (3) from the evaporator inlet tube (5).
15. Remove the evaporator inlet tube from the evaporator.
16. Remove the O-ring seal.



17. Remove the retaining nut (4) from the evaporator outlet tube (3).
18. Remove the evaporator outlet tube from the evaporator.
19. Remove the O-ring seal.



20. Remove the evaporator and blower module assembly (3).

1. Install the evaporator and blower module assembly (3).

Notice: Refer to Fastener Notice in the Preface section.

2. Install the evaporator and blower module assembly retaining nuts (2).

Tighten
Tighten the nuts to 6 N·m (53 lb in).

3. Install new O-ring seals to the evaporator inlet and outlet tubes. Refer to O-Ring Replacement .



4. Install the evaporator inlet tube (4) to the evaporator.
5. Install the evaporator inlet tube retaining nut.

Tighten
Tighten the nut to 18 N·m (13 lb ft).




6. Install the evaporator outlet tube (3) to the evaporator.
7. Install the evaporator outlet tube retaining nut.

Tighten
Tighten the nut to 18 N·m (13 lb ft).




8. Install the accumulator (5) to the bracket.
9. Install the nuts (3) to the accumulator retaining bracket.

Tighten
Tighten the nuts to 9 N·m (80 lb in).

10. Connect the low pressure sensor electrical connector.
11. Install new O-ring seals. Refer to O-Ring Replacement .
12. Install the evaporator outlet hose.
13. Install the evaporator outlet hose retaining nut (5) to the accumulator.

Tighten
Tighten the nut to 18 N·m (13 lb ft).

14. Install the compressor inlet hose.



15. Install the compressor inlet hose retaining nut (2) to the accumulator.

Tighten
Tighten the nut to 18 N·m (13 lb ft).

16. Install the multi-use module bracket. Refer to the appropriate procedure:

•	Multiuse Module Bracket Replacement for the 8.1L engine

•	Multiuse Module Bracket Replacement for the 7.8L engine

•	Caterpillar® 3126 Unit Repair Manual

17. Connect the low pressure sensor electrical connector.
18. Connect the blower motor assembly electrical connector.
19. Connect the blower motor resistor assembly electrical connector.
20. Install the air cleaner. Refer to the appropriate procedure:

•	Air Cleaner Replacement for the 6.6L (LBZ and LLY) engine

•	Air Cleaner Replacement for the 8.1L engine

•	Air Cleaner Replacement for the 7.8L engine

•	Caterpillar® 3126 Unit Repair Manual for the 7.2L (Caterpillar) engine

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