What is the correct sequence for evacuating an A/C system?

The correct sequence for evacuating an A/C system is all about ensuring that the system is properly prepared for evacuation, allowing for any moisture and contaminants to be removed efficiently.

Initially, connecting both the gauge manifold and a micron gauge is critical as it allows for accurate monitoring of the vacuum level being achieved in the system. Opening the service ports is the next step which permits the vacuum pump to draw air and moisture out from within the A/C system effectively. Turning on the vacuum pump follows, which is the core action of initiating the evacuation process. After this, opening the manifold gauge valves enables the system to create a vacuum, and this is crucial in ensuring that all parts of the system are exposed to the vacuum that is being generated. Lastly, closing the second stage of the vacuum pump, if it is a two-stage pump, helps ensure that the vacuum is maintained in the system, and the removal of moisture is optimized.

This methodical approach ensures that all components of the A/C system are evacuated properly, which is essential for preventing contamination and ensuring optimal performance after the system is recharged with refrigerant.