Service Port HVAC: Description and Operation

REFRIGERANT SYSTEM SERVICE PORT
The two refrigerant system service ports are used to charge, recover/recycle, evacuate, and test the air conditioning refrigerant system. Unique service port coupler sizes are used on the R-134a system, to ensure that the refrigerant system is not accidentally contaminated by the use of the wrong refrigerant (R-12), or refrigerant system service equipment.

The high pressure service port is located on the liquid line between the condenser and the evaporator, near the front of the engine compartment. The low pressure service port is located on the suction line, near the accumulator outlet.

Each of the service ports has a threaded plastic protective cap installed over it from the factory After servicing the refrigerant system, always reinstall both of the service port caps.