Possible solutions for water leaks on passenger side

JTrigg

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Texas
Specific to a 99 Wrangler Sport with AC, 4.0. But probably carryover to other years and models....

All the things I addressed to finally get it stopped, some likely not the problem, but all were potentially issues and I am sure there was a combo assault, as I got the leaking from one area to stop, but not until I addressed the last issue has it (so far) stopped altogether...

Items needed / used (other than tools): FlexSeal in the spray can, and any basic general purpose adhesive in a tube. The adhesive is used as a caulking material....

1. Add a hose to your AC drain vent, which is currently just a short stub poking out of firewall under on the passenger side. The theory was in some conditions rain, or surface water, could blow back up into it, or wind could push the condensate back in.

The following issues address the foam insulation material around these parts and areas, which on a 1999 jeep is worn, brittle, and flaking away....

2. Flex seal the entire area where the AC tubing enters the cab from the firewall. That is foam and has likely pulled away from the tubing.

3. The cabin air intake is located under the plate between windshield and hood. It is raised, so water normally won't enter it unless the area is full of leaves and debris (which it may be). However, 3 screws hold down the plastic housing, and there is a gap between it, and the "funnel" into the ventilation system. It is filled with the foam, most likely crumbling, so put the adhesive in, or otherwise caulk up the gap.

4. Remove the battery, and look under it to the fan motor housing. It sits in a little concave area with, again, some foam insulation around it. Flex seal the area.

If you look at my past postings, and probably elsewhere on this forum, you can find a step by step to removing the cover plate between hood and windshield....
 
a couple a months ago i did almost the same thing exept removing the cover plate . at mine tj the foam insulation was crumbling. i replaced it with flex seal.

maybe i will remove the cover plate(y). thanks for your writing.
 
I removed the cowl a few weeks ago after I woke up to some puddles on my passenger floor mat and found it to be pretty clean BUT the foam gasket around the air intake was a little damp.

I took that opportunity to removed the air intake which is just held in by 3 screws, let it dry off after I cleaned all the dirt and dust off of it, reinstalled with very good waterproof silicone sealant and haven't had any issues again. I'll have to check under the battery and the lines where the AC tubes come in. (y)
 
Well I cleaned the vent and re sealed the cabin air intake, see if that fixes the problem. I’ll probably also throw a hose on the A/C drain and look at the foam around it. Just have to wait for it to rain again down here.
Thanks for the thread, really useful.
 
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When I had my 99 it leaked back into the passenger floorboard. Took it back to the dealer and they said nothing was wrong with it. Had a friend look at it and he immediately noticed the condensation drain was level coming out of the firewall. Went to the auto parts store bought a short 5/8 elbow and a hose clamp and never had a wet floorboard again. The 2000 or 01 have an elbow.
 
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Same here, very humid in the Carolina's, the foam around the AC drain was crumbling and the AC was pumping out a lot of water from the humidity. At highway speeds the water blew back down the short ac drain into the cab. Put the 90 degree elbow and an extension pipe, never had the issue again, never sealed the foam around the AC drain
 
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I used 3/4" pvc 90° elbow pipe fitting on the ac drain sealed it to the firewall with gasket maker ,all good ever since 👍
 
I'm not gonna post the old "This thread is useless without pics." emoji (or whatever u call it). But pics would make this most even better.

Its an excellent post though. As Im chasing a similar leak.
 
I think I’ve got the same issue. Mine is leaking at the firewall. Pouring in pretty good regardless of motion so it’s not wind blowing back in. Should I cut out the existing foam and then work in silicon?
 
I think I’ve got the same issue. Mine is leaking at the firewall. Pouring in pretty good regardless of motion so it’s not wind blowing back in. Should I cut out the existing foam and then work in silicon?
 
437101E4-EE04-44B4-8572-D4302309B070.jpeg
 
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take your cowl cover off infront of the windsheild there is a trap for crud and water to go out through get ur air compressor and blow it out.
 
take your cowl cover off infront of the windsheild there is a trap for crud and water to go out through get ur air compressor and blow it out.
I use a metal clothes hanger and straighten it and use it to push debris out the bottom of the drain.
 
Fixed. I blew out the cowl and this helped a ton but I still had a small leak into the floor so I sealed around the old foam that goes around the spot where it punches through the firewall and that stopped it. Good to go, thanks!