Service Port HVAC: Description and Operation
SERVICE PORT VALVE COREDESCRIPTION
The A/C service port valve cores are serviceable items. The high side valve is located on the located on the manifold directly over the discharge port of the A/C compressor. The low side valve is located on the liquid line near the evaporator inlet tube at the rear of the engine compartment.
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 A/C discharge. The low-side service port is located on the A/C liquid line. Both the high-side and low-side A/ service port valve cores are serviceable.
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.