Expansion Block/Orifice Tube: Service and Repair
EXPANSION (ORIFICE) TUBE REPLACEMENTTOOLS REQUIRED
- J 39400-A Halogen Leak Detector
- J 26549-E Orifice Tube Remover
REMOVAL PROCEDURE
IMPORTANT: When you replace an expansion (orifice) tube, compare the design of the orifice tube to the design of the replacement part for the correct selection. The different styles of orifice tubes are not interchangeable.
1. Recover the refrigerant.
2. Raise the vehicle. Refer to Vehicle Lifting.
3. Remove the bolt holding the evaporator hose assembly to the condenser.
4. Remove the evaporator hose assembly from the condenser.
5. Remove and discard the seal washer.
IMPORTANT: Immediately cap or tape the open end of the condenser line to prevent contamination.
6. Use J 26549-E to remove the orifice tube.
7. Use the following procedure in order to remove a restricted or plugged expansion (orifice) tube:
7.1. Remove as much as possible of the impacted residue.
7.2. Use a heat gun in order to apply heat to the expansion (orifice) tube. Apply the heat approximately 7 mm (1/4 in) from the dimples on the inlet pipe.
7.3. While applying heat, use pliers in order to grip the orifice tube. Use a turning motion along with a push-pull motion. This will loosen the impacted orifice tube and remove the tube.
7.4. Swab the inside of the evaporator inlet line to clean any contamination from the line.
8. Inspect the expansion orifice tube for the following conditions and clean or replace with a new tube as indicated:
- Broken plastic frame; replace tube
- Filter screen (1,2) torn, damaged or plugged with fine gritty material; replace tube
- Brass orifice tube (3) damaged or plugged; replace 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
1. Lightly coat the new orifice tube O-ring seal (4) with mineral base 525 viscosity refrigerant oil.
2. Remove the cap or tape from the evaporator line.
3. Using J 26549-E, CAREFULLY grasp the edge of the expansion orifice tube (long filter screen (1) inlet side of tube).
4. Insert the orifice tube into the evaporator line, beginning with the short filter screen (2) outlet side.
5. Remove the cap or tape from the condenser line.
6. Using a lint-free clean, dry cloth, carefully clean the sealing surfaces of the line fittings.
7. Install a new seal washer on the condenser tube.
8. Install the evaporator hose assembly to the condenser. Install the evaporator hose assembly bolt to the condenser.
NOTE: Refer to Fastener Notice in Service Precautions.
Tighten
Tighten the bolt to 25 N.m (18 lb ft).
9. Lower the vehicle.
10. Evacuate and charge the A/C system.
11. Leak test the fittings of the component using the J 39400-A.