Operation CHARM: Car repair manuals for everyone.

Operation







OPERATION

The variable A/C orifice tube provides improved A/C system cooling during city driving and when under heavy loads by controlling refrigerant flow through the two parallel flow paths integral to the orifice tube. Under normal loads, the refrigerant flows through the inlet filter screen, the fixed and variable ports and both metering orifices. As the load on the A/C system increases, the temperature of the refrigerant leaving the A/C condenser increases, which causes the bi-metal coil to expand and restrict the flow of refrigerant through the variable port of the tube. Restricting the flow of refrigerant through the variable port and its orifice provides a greater pressure differential between the high and low pressure sides of the A/C system, resulting in colder refrigerant vapor traveling through the A/C evaporator to help remove the heat from the conditioned air flowing into the passenger compartment.

The A/C orifice tube is not serviceable and the A/C liquid line must be replaced if the orifice tube is found inoperative Description and Operation.