How to Perform Pressure Testing and Leak Detection for Car Air Conditioning?
2 Answers
Car air conditioning pressure testing and leak detection operations are as follows: 1. Correctly connect the air conditioning pressure gauge to the high and low pressure pipelines of the air conditioning system (red for high pressure, blue for low pressure), then connect the air pump for pressurization. 2. After pressurization is completed, close the high and low pressure valves of the pressure gauge, let it stand for 10-15 minutes, observe the pointer of the pressure gauge to check if there is any leakage in the air conditioning system, and locate the leak point. Precautions for pressure testing and leak detection are as follows: 1. The pressure for car air conditioning testing is generally around 20-30 Bar, which is higher than the working pressure of the car air conditioning system. 2. Note that vacuuming and refrigerant charging can only be performed after leak detection. After completing pressure testing, leak detection, and vacuuming, you can directly add the refrigerant.
As an experienced auto repair technician, I frequently perform AC pressure leak tests. The process starts with evacuating the system to ensure no residual refrigerant remains. Then connect the nitrogen cylinder and pressure gauge, pressurize to around 150 PSI, and maintain stable pressure for several minutes. If the pressure drops, there's definitely a leak. At this point, spray soapy water on all connections like evaporator or compressor interfaces - bubbles indicate the leak source. After fixing the leak, repeat the test until pressure holds steady. The tools are simple: just a pressure pump and soapy water bottle. Safety first: never use oxygen (it's flammable); wear gloves and goggles to avoid gas splashes. The whole process takes about 20 minutes, then recharge with new refrigerant. Remember to work in ventilated areas, never in enclosed garages. Regular leak testing prevents AC failures and extends component lifespan.
