How to Detect Refrigerant Leakage in Car Air Conditioning?
2 Answers
There are several methods to detect refrigerant leakage: 1. Visual Inspection: This is the simplest and most primitive method, but also the least effective. Very minor leaks may not be detectable at all. 2. Electronic Leak Detection: This is a new and popular method in recent years. A detection probe is moved around potential leakage areas, and an alarm from the device indicates a significant leak. However, electronic detection can be affected by external factors like gasoline, exhaust fumes, or odors, which may lead to incorrect detection. 3. Water Immersion Test: Commonly used for components like compressors, condensers, and evaporators. The method involves filling these parts with compressed air and then immersing them in warm water (around 50 degrees Celsius) to observe for bubbles. Warm water is used to reduce surface tension, as colder water has higher surface tension, making minor leaks harder to detect. 4. Fluorescent Leak Detection: This method uses fluorescent dye that emits bright yellow-green light under UV/blue light. The dye is added to the air conditioning system in a specific ratio. After running the system, a UV lamp and special glasses are used to detect leaks, which appear as yellow fluorescence. The advantages of fluorescent detection include accurate localization, visible leakage points, simplicity, portability, and low repair costs.
I went through the AC refrigerant leak issue last summer. The most basic method is to buy a bottle of AC-specific fluorescent dye and add it to the refrigerant. Run the AC for half an hour, then use a UV flashlight to inspect pipe connections and the condenser—any green fluorescence indicates the leak point. The soapy water test also works: spray a mixture of dish soap and water on suspected pipe connections, and bubbling spots are definite leaks. If possible, you can rent an electronic leak detector and slowly scan along the AC lines like mine sweeping—it beeps when a leak is detected. If the evaporator is leaking internally, it’s more troublesome as the dashboard needs to be removed. So I recommend first using a pressure gauge to check the system’s pressure retention and confirm the leak before disassembling. If you can’t handle it yourself, just head to a repair shop—they use helium mass spectrometers for more accurate detection.
