Summary of Auto AC Maintenance and Common Faults and Case Analysis of Automobile Air Conditioning 18

Pressure judgment failure

If the high pressure gauge shows normal pressure and the low pressure gauge shows high pressure, it means that the auto ac evaporator pressure regulator, hot gas bypass valve, and intake throttle valve are faulty or adjusted;

If the discharge air temperature is high, and the pressure gauge indicates normal, or high, and the low pressure increases slightly, the expansion valve filter is blocked;

If the high pressure gauge indicates above normal pressure, the low pressure gauge indicates below normal pressure, and the receiver dryer and lines are frozen, the receiver dryer screen is clogged.

If the high pressure gauge indicates above normal pressure, there may be excess moisture in the system. If air bubbles are found in the viewing window, air is in the system.

Adjustment of expansion valve

When the opening of the expansion valve is large or small, it can be adjusted. The large opening means that the low pressure is a little high, and the high pressure is low but not obvious, and the cooling effect is not good. If the opening is small, the high pressure is high, and the low pressure is low [the most obvious increase in oil]. The surface of the pipeline is also easy to frost.... There is a hole on the side of the expansion valve, which can be adjusted with a tool. [Tighten] inward is to reduce it, and vice versa.

auto expansion valve

 


Post time: Feb-07-2022