GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 26549-E Orifice Tube Remover
    • J 39400-A Halogen Leak Detector

Removal Procedure


    Object Number: 621746  Size: SH
  1. Recover the refrigerant from the A/C system. Refer to Refrigerant Recovery and Recharging .
  2. Remove the front evaporator tube to rear evaporator tube retaining bolt.
  3. Important: Cap or tape the open A/C Components immediately to prevent system contamination.

  4. Disconnect the front evaporator tube from the rear evaporator tube.
  5. Remove and discard the O-ring.
  6. Cap or tape the rear evaporator tube.

  7. Object Number: 621750  Size: SH
  8. Using J 26549-E remove the orifice tube.

  9. Object Number: 296238  Size: SH
  10. Inspect the expansion (orifice) tube for the following conditions and clean or replace with a new tube as indicated:
  11. • Broken plastic frame; replace the tube
    • Filter screen (1, 2) torn, damaged or plugged with fine gritty material; replace the tube
    • Brass orifice tube (3) damaged or plugged; replace the tube
    • Filter screen (1) coated with metal chips, flakes or slivers; coating may be removed with low pressure shop air and reused if cleaned satisfactorily
    • If reusing the orifice tube, install a new O-ring (4)

Installation Procedure


    Object Number: 621750  Size: SH
  1. Remove the cap or tape from the rear evaporator tube.
  2. Install the tube (short filter screen outlet side first) fully into the front evaporator tube.
  3. Install new O-rings to the expansion tube. Refer to O-Ring Replacement

  4. Object Number: 621746  Size: SH
  5. Connect the front evaporator tube to the rear evaporator tube.
  6. 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.

  7. Install the front evaporator tube to rear evaporator tube retaining bolt.
  8. Tighten
    Tighten the bolt to 25 N·m (18 lb ft).

  9. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging .
  10. Leak test the fittings of the component using J 39400-A .