How to Test the Pressure of a Car Air Conditioner?
2 Answers
Car air conditioner pressure testing methods are as follows: 1. Use a pressure gauge to check car air conditioning refrigeration system faults: Generally divided into two states when the compressor is stopped and running. After the compressor has been stopped for more than 10 hours, the high and low pressures of the compressor should be the same value. If the displayed high and low pressure values are not equal, it indicates there is a blockage inside the system, and the expansion valve, liquid storage bottle, and pipeline parts should be checked. 2. When the compressor is in operation: Control the engine speed at 1500-2000r/min, start the air conditioner to make the compressor work. Under normal circumstances, the low-pressure side pressure is about 150-250kpa, and the high-pressure side pressure is about 1400-1600kpa.
Testing car AC pressure is quite simple, I often do it myself. First you need a manifold gauge set, usually available at auto parts stores or online. Locate the high and low pressure service ports on your vehicle - positions vary by model, typically near the compressor in the engine bay. After connecting the gauges, start the engine and turn the AC to max cooling with fans running. Reference values depend on your specific model, but generally low pressure should be 10-30 psi and high pressure 150-300 psi. Readings too high may indicate overcharged refrigerant or blockage, while low readings suggest leaks or insufficient refrigerant. Disconnect gauges slowly after testing to avoid refrigerant spray. Regular checks can detect AC issues early, saving money and ensuring safety. I helped a neighbor diagnose a condenser leak on an old Ford using this method - the whole process took about half an hour.
