I have a Mercedes A Class 63 reg. (no sunroof) and water leaks inside and onto the carpet on the passenger side; the back is soaking wet. I took it to the garage, and they said it might be a blocked AC drain as the pollen filter was absolutely soaked. They cleared the debris, and then they did a water test, and the problem was sorted. A few weeks later the problem is back! Is it really blocked drains or something more serious?
Yes, it could be a blocked drain. Since the mechanic only temporarily cleared the drain, it's like pushing the hair back down the tub drain without removing it from the tub; it will flow back down the drain and will clog it again. You could keep clearing it with a coat hanger or have the evaporator removed and have it completely cleaned of debris, but that costs a few bucks. They will need to discharge the AC system and remove the evaporator box from behind the dash.
Updated on March 22, 2018
By Eddie Carrara