Expansion Block/Orifice Tube: Testing and Inspection

A/C ORIFICE TUBE

WARNING: THE LIQUID LINE BETWEEN THE CONDENSER OUTLET AND THE A/C ORIFICE TUBE CAN BECOME HOT ENOUGH TO BURN THE SKIN. USE EXTREME CAUTION WHEN PERFORMING THE FOLLOWING TEST.

NOTE: The A/C orifice tube can be checked for proper operation using the following procedure. However, the A/C orifice tube is only serviced as a part of the liquid line. If the results of this test indicate that the A/C orifice tube is obstructed or missing, the liquid line must be replaced.

1. Confirm that the refrigerant system is properly charged.
2. Start the engine. Turn on the air conditioning system and confirm that the compressor clutch is engaged.
3. Allow the air conditioning system to operate for five minutes.
4. Lightly and cautiously touch the liquid line near the condenser outlet at the front of the engine compartment. The liquid line should be hot to the touch.
5. Touch the liquid line near the evaporator inlet at the rear of the engine compartment. The liquid line should be cold to the touch.
6. If there is a distinct temperature differential between the two ends of the liquid line, the A/C orifice tube is in good condition. If there is little or no detectable temperature differential between the two ends of the liquid line, the A/C orifice tube is obstructed or missing and the liquid line must be replaced.