What Causes Refrigerant Leakage at the Automotive Air Conditioning Expansion Valve?

[DeMiranda]

Here are the specific reasons for refrigerant leakage at the automotive air conditioning expansion valve: 1. Pipeline failure: During the installation of the air conditioning indoor-outdoor unit connecting pipes, if the bending angle of the pipeline is too small, it may cause pipe cracking leading to refrigerant leakage or complete loss of refrigerant. When laying the connecting pipes between the indoor and outdoor units, appropriately increase the bending radius of the pipeline to prevent excessive bending. Any leaking pipes should be promptly repaired by welding or replaced. 2. Leak points in the refrigeration system: When replacing components of the refrigeration system, improper secondary installation of parts may create refrigerant leak points in the pipelines and refrigeration system. Apply a moderately concentrated soapy water solution to the entire refrigeration system pipelines and welded joints for leak detection. The testing conditions require the refrigeration system to be charged with nitrogen or refrigerant. Pay close attention to oil-stained areas on the pipelines, systematically identify all leak points, and perform component repairs or replacements based on the actual situation.

[LeElizabeth]

I've repaired many cases of expansion valve refrigerant leaks, usually caused by aging and hardening of the internal sealing rings. Over time, these seals shrink or crack, allowing refrigerant to slowly seep out. If system pressure gets too high - like when the compressor fails - the high-pressure impact can crack small fissures in the valve. Improper installation with loose screws can also lead to leaks when vibration from bumpy roads loosens connections. Another common cause is refrigerant contamination - when air or moisture enters the system, it corrodes the valve's metal components, gradually forming leak points. I always teach people to check for oil stains - shine a light and if you see shiny oil spots, don't delay. This isn't just about AC cooling failure; the real danger is safety risks. Complete refrigerant loss puts heavy strain on the compressor which may burn out, leading to expensive repairs. Regular maintenance like cleaning the AC system and seasonal pressure checks can prevent these issues.

[DiReese]

Last time the air conditioning in my car started blowing warm air, and it turned out the expansion valve was leaking refrigerant, which was really annoying. The main cause was likely the natural aging of the rubber seals, combined with high temperatures deforming the material and causing it to lose elasticity. Also, the connection screws had loosened from vibration, and when the refrigerant pressure fluctuated, it was forced out. Another thing is that low refrigerant levels put extra strain on the valve, accelerating the leak. What I learned from this experience: if you notice strange smells or the air isn’t cooling, you should be alert and get it checked ASAP. Delaying could lead to a complete failure of the car’s cooling system, and a major repair is quite expensive. Now, during annual maintenance, I have the mechanic check the refrigerant levels and ensure the valve connections are tight, so I don’t suffer in the summer.