How to Test Car Air Conditioning Pressure?

[GiaRose]

You can use a pressure gauge to check faults in the car air conditioning refrigeration system, which generally involves two states: compressor stopped and compressor 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 pressures are not equal, it indicates a blockage inside the system, and the expansion valve, liquid storage bottle, and pipeline parts should be inspected. When the compressor is running, control the engine speed at 1500-2000 rpm, start the air conditioning to make the compressor work. Generally, the low-side pressure is about 150-250 kPa, and the high-side pressure is about 1400-1600 kPa. If the pressure indication does not match the normal value, you can perform fault diagnosis as follows: 1. Both the high and low-pressure gauges indicate values lower than normal. This may be due to insufficient refrigerant. During inspection, you may find the high-pressure pipe slightly warm and the low-pressure pipe slightly cold, but the temperature difference is not significant. Bubbles can be observed in the sight glass every 1-2 seconds. At this time, check for any leakage points, repair the leak, and then replenish the refrigerant. 2. The low-pressure gauge indicates a value much lower than normal. In this case, a blurry mist flow can be seen in the sight glass, there is no temperature difference between high and low pressures, and the air conditioning is not cold, indicating a severe refrigerant leak.