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 air cleaner layer. Refer to the appropriate procedure:

•	Air Cleaner Replacement in Engine Controls-6.6L.

•	Air Cleaner Replacement in Engine Controls-8.1L.

•	Air Cleaner Replacement in Engine Controls-7.8L.

•	Caterpillar® 3126 Unit Repair Manual

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 accumulator. Refer to Air Conditioning Accumulator Replacement .
8. Remove the multi-use module bracket. Refer to the appropriate procedure:

•	Multiuse Module Bracket Replacement in Engine Controls-6.6L.

•	Multiuse Module Bracket Replacement in Engine Controls-8.1L.

•	Multiuse Module Bracket Replacement in Engine Controls-7.8L.

•	Caterpillar® 3126 Unit Repair Manual




9. Remove the retaining nut (3) from the evaporator inlet tube (5).
10. Remove the evaporator inlet tube from the evaporator.
11. Remove the sealing washer.



12. Remove the retaining nut (4) from the evaporator outlet tube (3).
13. Remove the evaporator outlet tube from the evaporator.
14. Remove the sealing washer.



15. Remove the front cover retaining screws from the evaporator and blower module assembly.
16. Remove the front cover.
17. Remove the evaporator core from the evaporator and blower module assembly.

1. Add PAG oil to the EVAP core. Refer to Refrigerant System Capacities .



2. Install the evaporator core to the evaporator and blower module assembly.
3. Install the front cover.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

4. Install the front cover retaining screws to the evaporator and blower module assembly.

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

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



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

Tighten
Tighten the nut to 16 N·m (12 lb ft).




8. Install the evaporator outlet tube to the evaporator.
9. Install the evaporator outlet tube retaining nut.

Tighten
Tighten the nut to 16 N·m (12 lb ft).

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

•	Multiuse Module Bracket Replacement in Engine Controls-6.6L.

•	Multiuse Module Bracket Replacement in Engine Controls-8.1L.

•	Multiuse Module Bracket Replacement in Engine Controls-7.8L.

•	Caterpillar® 3126 Unit Repair Manual

11. Install the accumulator. Refer to Air Conditioning Accumulator Replacement .
12. Connect the low pressure sensor electrical connector.
13. Connect the blower motor assembly electrical connector.
14. Connect the blower motor resistor assembly electrical connector.
15. Install the air cleaner layer. Refer to the appropriate procedure:

•	Air Cleaner Replacement in Engine Controls-6.6L.

•	Air Cleaner Replacement in Engine Controls-8.1L.

•	Air Cleaner Replacement in Engine Controls-7.8L.

•	Caterpillar® 3126 Unit Repair Manual

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