Service Port HVAC: Description and Operation

Refrigerant system service ports are used to recover, recycle, evacuate, charge and test the A/C refrigerant system. Unique sizes are used on the two service ports for the R-134a refrigerant system to ensure the system is not accidentally contaminated with R-12 refrigerant or by service equipment used for R-12 refrigerant.

The high side service port is located on the front section of the liquid line near the receiver/drier. The low side service port is located on the A/C suction line near the A/C compressor. The low side A/C service port valve core is serviceable, however, the high side A/C service port valve core is not. If the high side service port valve core is faulty or damaged, the front section of the liquid line will require replacement.

NOTE: The protective cap aids in service port sealing and helps protects the refrigerant system from contamination. Remember to always reinstall the protective cap onto the service port when refrigerant system service is complete.

Each of the service ports has a threaded plastic protective cap installed over it from the factory. The service port caps are serviceable items.