Automotive Air Conditioning Information Forum (Archives)

Greengone on Mon March 26, 2012 2:03 PM

Year: 2002
Make: Pont
Model: Montana
Engine Size: 3.4

I've got a water leak on the passenger side under the carpet and sound insulation.

No water when the van is left in the rain (I don't have a garage). I haven't used the AC since last fall, but will soon need it again.

I removed some trim around the floor and on the underside of the dash. I can't see the drain with what I've removed so far.

I accessed library-level repair books and on-line info, which have lots of info on disassembly repair, etc of the major AC components, but no discussion of the drain or its location. Is it possible for it to be plugged? Can it be unplugged? Is it common for the evap case to crack?

I would appreciate any suggestions. I don't want to tackle removing the dash, but I do need to fix the AC (which cools nicely) soon.

Cussboy on Mon March 26, 2012 2:37 PM

Most (maybe all) evaporators have a rubber drain tube at their bottom, which routes to under the vehicle (outside of the cabin) to dump that condensate (formed from humidity condensing out of the cabin air, of course).

That rubber tube can become dislodged, so condensate drains into the cabin. Or the drain can get plugged with dirt, mold, etc. First thing is to see if that tube is connected. If so, and if you know how to re-route it, you could remove it for cleaning or simple replacement (vacuum tubing, or fuel line). It may not be in a straight configuration, so not so easy to stick a wire up there, and you sure don't want to puncture the evaporator by forcing a wire or rod up there.

Greengone on Tue March 27, 2012 10:37 PM

I was hoping that someone with experience with the Pontiac Montana could tell me where to look for the tube. I have removed the dash underside trim and pulled back the carpet and rubber foam insulation, but haven't seen any sign of the tube, either connected or hanging loose. As soon as we have warm weather, I will run the AC while laying in the passenger floor to try to see where the water comes from. But so far, no luck.