Tools Required

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 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

3. Remove the evaporator inlet tube retaining nut from the evaporator.
4. Use the J 26549-E in order to remove the expansion tube (1).
5. If the expansion tube is stuck perform the following:

•	Remove as much of the impacted residue as possible.

•	Carefully apply heat with a heat gun, or hair dryer 7 mm (0.25 in) from the dimples on the inlet pipe.

•	DO NOT overheat the pipe.

•	While applying heat, use the J 26549-E in order to grip the expansion tube. Use a turning motion along with a push-pull motion to loosen the impacted expansion tube and remove.

Important: 

•	Install the shorter screen end (3) first into the evaporator.

•	Coat the O-ring seal (2) with 525 viscosity refrigerant oil.

1. Use the J 26549-E in order to install the expansion tube.
2. Install new sealing washers to the evaporator tube. Refer to Sealing Washer Replacement .
3. Install the evaporator tube to the evaporator.

Notice: Refer to Fastener Notice in the Preface section.

4. Install the evaporator tube retaining nut to the evaporator.

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

5. 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

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 .