GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2004 🢒 TopKick C-Series (Conventional) C4/C5 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 Expansion (Orifice) Tube Replacement

Tools Required

    • J 26549-E Orifice Tube Remover and Installer
    • 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 layer. Refer to the appropriate procedure:
    3. •  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
  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:
    6. • 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.

Installation Procedure

    Object Number: 82109 Size: SH

    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.

    4. 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 evaporator tube retaining nut to the evaporator.

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

  5. Install the air cleaner layer. Refer to the appropriate procedure:
    6. •  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
  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 .