Yes, it is possible to vacuum the car's air conditioning (AC) system without venting the refrigerant into the atmosphere. This process is known as "evacuating" the system, and it's commonly done when performing AC maintenance or repairs. The goal is to remove any air and moisture from the system, which can negatively impact its cooling performance.
To do this properly and avoid venting the refrigerant, you will need a vacuum pump and a set of manifold gauges. Here's a general outline of the steps involved:
Obtain the necessary tools: You'll need a vacuum pump capable of pulling a sufficient vacuum on the AC system and a set of manifold gauges to connect to the low and high-pressure service ports on the AC lines.
Locate the low and high-pressure service ports: In most cars, the low-pressure service port is larger and located on the larger diameter line, while the high-pressure service port is on the smaller diameter line. Refer to your car's manual or consult a repair guide to find their specific locations.
Connect the manifold gauges: Attach the low-pressure side (blue hose) of the manifold gauges to the low-pressure service port and the high-pressure side (red hose) to the high-pressure service port. The yellow hose on the manifold gauges should be left open to the atmosphere.
Open the valves on the manifold gauges: Turn both the low and high-pressure knobs on the manifold gauges counterclockwise to allow the system to connect to the gauges.
Start the vacuum pump: Connect the vacuum pump to the yellow hose on the manifold gauges and start the pump. The pump will begin pulling a vacuum on the AC system.
Monitor the gauges: Watch the gauges for at least 15-30 minutes. The low-pressure side gauge should show a steady vacuum reading, and the high-pressure side gauge should remain at or near zero.
Close the manifold gauge valves: After sufficient time has passed, turn off the vacuum pump and close the low and high-pressure knobs on the manifold gauges.
Check for vacuum hold: Allow the system to sit for a few minutes to check for any significant pressure rise. If the vacuum holds steady, it indicates that there are no significant leaks in the system.
Once the system has been successfully evacuated, you can recharge it with the appropriate amount of refrigerant, ensuring it operates efficiently and cools effectively without wasting refrigerant. If you are not familiar with the process or lack the necessary tools, it's best to seek the help of a professional AC technician to perform the evacuation and recharge for you. They can ensure the proper handling of the refrigerant and the integrity of the AC system.