Summary of Auto AC Maintenance and Common Faults and Case Analysis of Automobile Air Conditioning 20

4 The air-conditioning of the car air conditioner is insufficient, the temperature at the outlet is not low, and the reading on the high pressure gauge is high. low pressure gauge

After investigation, the cause of the failure: the opening of the expansion valve is too small, the amount of the refrigerator flowing into the evaporator is small, and the heat of the air is not absorbed by the evaporation, so that the air-conditioning in the car is insufficient.

Treatment method: adjust the adjusting screw on the expansion valve and turn it counterclockwise to increase the refrigerant flow


Car air conditioning is not enough

The evaporator is frosted, and the readings of the high-pressure and low-pressure gauges are low. After investigation, the cause of the failure: the throttle hole in the expansion valve does not have the function of throttling and depressurization, so that the liquid refrigerant in the evaporator cannot be cooled well, so the vehicle temperature is high

Treatment method: release the refrigerant, replace with a new expansion valve, and refill the refrigerant.


After the car air-conditioning compressor runs for a period of time, the temperature in the car gradually drops, and the reading on the high pressure gauge is high. The cause of the fault is that the desiccant in the liquid storage cylinder penetrates water, which causes the expansion valve orifice to freeze, making the refrigerant not flow. The density of the refrigerant in the high-pressure pipeline increases gradually, and the high-pressure indication increases; the refrigerant density in the low-pressure system gradually decreases, and the low-pressure indication is low.

Treatment method: empty the system, replace the liquid storage tank, and refill the liquid to ensure that the system is free of water and gas.


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Post time: Apr-02-2022