Service Port HVAC: Description and Operation

The A/C service port valves on R-134a systems are of the one-piece design. The top portion of the fitting is aluminum and is threaded into a steel body on the suction accumulator/drier or on the refrigerant line and sealed with an O-ring. Two special service tools have been developed to aid in servicing of the access gauge port valves. They are the high side A/C fitting socket tool No. D94L-19703-A, or equivalent and low side A/C fitting socket tool No. D94L-19703-B, or equivalent. The high side fitting is the largest of the two valves. Both valves require special adapters to attach service equipment to the A/C system.