What to Do If the Car's Evaporator Box is Leaking?
3 Answers
During normal operation of the evaporator box, small water droplets may form due to condensation when warm air meets cold surfaces. Turn off the air conditioning and check if water continues to drip. If water still drips after turning off the air conditioning, it indicates poor sealing of the evaporator box, and a new evaporator box needs to be replaced.
I usually enjoy tinkering with minor car issues. Most cases of evaporator leakage are caused by clogged drainage pipes, where dust and debris accumulate over prolonged AC use, preventing water from draining. You can fix it yourself: park and turn off the engine, locate the drain hole under the evaporator (usually near the firewall), and carefully unclog it using a thin wire or compressed air gun—avoid excessive force to prevent pipe damage. If leakage persists after unclogging, it might indicate a cracked pipe or aged sealing gasket, requiring replacement parts. Ignoring leaks can soak the cabin carpet, fostering mold growth, unpleasant odors, and even short-circuiting wires, posing health risks and driving hazards. I recommend cleaning the drain hole every seasonal change and parking in a garage to minimize debris buildup—simple maintenance can prevent major headaches.
Last year, the evaporator in my car started leaking, causing the passenger footwell to accumulate water whenever the AC was on, which made my family and me worry about mold growth inside the car. I thought about trying to clean it myself first, but the drain hole was tightly clogged. In the end, I had to drive to the neighborhood repair shop where they used specialized tools to blow it clear. The mechanic warned me that such issues are common in summer and advised checking the drainage system every three to four months with a simple rinse to prevent clogs. Leaks not only make driving uncomfortable but can also corrode undercarriage parts, increasing repair costs. Now, I always check the AC condition during maintenance to avoid going through the hassle again.
