Reasons for Fluctuation in Low Pressure of Car Air Conditioning

[GiannaMarie]

If the high pressure rises and the low pressure drops after adding oil, the following possibilities exist: 1. Expansion valve blockage: Due to the failure of the dryer (receiver-drier), dirt or metal particles from compressor wear enter the expansion valve, causing blockage. It is recommended to replace the expansion valve and dryer, and perform a no-disassembly cleaning of the air conditioning system pipelines. 2. Temperature sensor switch failure: This keeps the valve in a normally closed state. The expansion valve and dryer need to be replaced. The most likely reasons for low low pressure: 1. Pipeline blockage causing insufficient refrigerant flow at low pressure. 2. Expansion valve failure preventing it from opening. 3. Insufficient refrigerant. All these can lead to insufficient refrigerant flow, resulting in low low pressure.