A.C. condensation leak

I have a 99 Suburban 5.7 2wd 120,000 miles and have found there is a condensation leak from under the passenger side dash where two metal tubes go through the firewall, it is water only no antifreeze mixed with it. It has just about ruined my carpet with stains. I was told there may be debris blocking water from coming out the correct area. I used an air hose to blow air into the exit point to clean it out and it still leaks. I can feel cold air and water exiting the correct hole. I was also told it may have a crack in it. I was also told There is also a 90 degree elbow tube that is supposed to go over this hole but it is missing, and that while I drive air is pushing some of the water back into the tube causing the leak. I would like to get this fixed before summer.
The last problem I posted about a misfire I fixed it with a new rotor and cap. The old one was not tightened all the way down and was corroded and worn. Thanks for your help.

Yes, you have to have the 90 degree tube on the drain-- you can substitute a hose- as long as it points down--- water back-up into car from condensation happens like you describe- but usually only after an hour or so drive without stopping- this gives it time to accumulate and back-up. I used to see this a lot on B-bodies (Caprice and Roadmaster) in early 90's- where the factory forgot to put on the drain elbow...

Do you typically drive for an hour or more at highway speeds when this happens?

Yes, after a long drive is when I notice it. I tried to buy one at the dealership but they said they did not sell it. I will try the salvage yard next. If that doesn't work I will fabricate one. Thank you very much for your help.

Go to the HELP! section in your autoparts store. They will be labeled for vacuum lines, but I've found one with a 1/2" ID elbow that'll fit.

I'll suggest you first try to clean any obstructions from that drain tube, if any.

I'd also suggest squirting some silicone caulk or sealant around the condenser tubes to help seal around them. Over time the original black foam breaks down, creating a nice big gap for air/water to get in. Helps reduce fatigue in the tube connections to the condenser due to vibration.

Thanks for the advice I was not sure the diameter of tube I would need. As far as obstructions I stuck a coat hanger back into it to check it out (probably a bad idea) and blew air into it. I also blew air into the rear tube after someone told me it might help. I had thought about putting marine caulk around the tubes, the foam is still entact. Do I seal it at the interior side, at the firewall? If I remove the screen under the wipers will that give me access to check for obstructions? Also I can feel cold air coming form the hole and it does drip water.

I have a 99 Suburban 5.7 2wd 120,000 miles and have found there is a condensation leak from under the passenger side dash where two metal tubes go through the firewall, it is water only no antifreeze mixed with it. It has just about ruined my carpet with stains. I was told there may be debris blocking water from coming out the correct area. I used an air hose to blow air into the exit point to clean it out and it still leaks. I can feel cold air and water exiting the correct hole. I was also told it may have a crack in it. I was also told There is also a 90 degree elbow tube that is supposed to go over this hole but it is missing, and that while I drive air is pushing some of the water back into the tube causing the leak. I would like to get this fixed before summer.
The last problem I posted about a misfire I fixed it with a new rotor and cap. The old one was not tightened all the way down and was corroded and worn. Thanks for your help.

what do the stains look like?? or is the carpet just "crispy" because of the water??

The stain is brown. I tried to clean it with a non commercial carpet cleaner machine and cleaning liquid. I was thinking about getting a professional to look at it

Removing the cowling will give some access to the fresh air intake for the A/C...it's still pretty convoluted on purpose to minimize sucking in leaves, etc. If you notice alot of leaves and dirt in the area underneath the cowling, the drainage holes on either side could be plugged. Clean it out and rinse the dirt out with water. You should see water draining from either side of the truck.

Looking into the engine bay at the firewall where the heater core pipes come through, shine a light from underneath the dash through that penetration. If you see light, you've got a leak. I would also look to see if there might be any open holes near there (I found one in my truck and plugged it with a snap-in cap).

Now go under the dash. If you can remove the bottom cover to the heater core, go in and check to see if there's alot of dirt. Clean it out with a sponge or vacuum. Also check the housing for the telltale drip signs. Finally, run a pipe cleaner through the drain hole to dislodge any dirt plugs and push them out instead of back into the heater core box. Hope this helps!