How to Deal with Water Ingress in Automotive Refrigeration System?
3 Answers
Methods for handling water ingress in the refrigeration system include: 1. Identify the cause of water ingress, which can be due to leaks in the condenser, leaks in the evaporator, or moisture in the added refrigerant; 2. If there is significant water ingress, disassemble the refrigeration system components, perform segmented purging, and finally restore the refrigeration system; 3. If the water ingress is not severe, simply identify the cause and replace the filter. The refrigeration system requires dry and clean pipelines. Once there is water in the pipelines or the moisture content in the refrigerant exceeds the standard, water can cause ice blockage during compression, damage the insulation of motors and wires, and lead to acidification of the refrigeration oil at high temperatures, resulting in copper plating. Water impurities can throttle the refrigerant flow in the system. If present in the refrigerant, they can clog the filter, causing high compressor return gas temperature. In the oil system, they can result in reduced or no oil return, ultimately leading to dry friction and burnout of the compressor.
Last time my car's AC vents sprayed water mist, it was because the drain hole was clogged. First, get down and check the position of the AC drain hole under the chassis. Use a wire to unclog the rubber tube, and once the water drains out, it should work immediately. If the compressor gets water inside, it could be a big problem—you'll need to pull out the fuse to prevent it from starting, then disassemble the AC pipes and use compressed air to dry the system. I've seen people pour anhydrous ethanol into the pipes to absorb moisture when repairing cars, but it's better not to do it yourself as it can corrode the seals. In an emergency, you can park the car on a slope and leave all doors open for ventilation for half a day. Most importantly, don't press the AC button until everything is completely dry and the refrigerant is replenished, otherwise, the compressor could seize up, and repairs could cost thousands.
For seasoned hands who've disassembled AC lines before, emulsified compressor oil from system moisture is the worst nightmare. First check if the low-pressure line feels cold to touch - if not, shut off the compressor immediately. My protocol involves replacing the entire receiver-drier and blowing nitrogen through all connections for ten minutes. No equipment? Try this field fix: Remove blower motor, stuff 5-6 packs of food-grade desiccant into evaporator box, then solar-bake the sealed cabin for three hours. The sneakiest case I've seen was condenser micro-leaks introducing moisture - that demands complete system disassembly for baking. Just bite the bullet and run a dedicated vacuum pump for two hours. Critical reminder: Always recharge with fresh compressor oil post-repair, or say goodbye to those bearings.
