the mysterious interior rain leak

[bluex]

The problem is with the HVAC black box underneath the cowl cover as mentioned three threads up. That black box below the cover consists of two plastic pieces, an upper one and a lower one that are attached and sealed with foam tape at the factory. The foam tape breaks down and the leaks begin. The problems is with getting good access to the box in order to repair the problem. LMG actually sells a replacement seal but I have yet to find a good way to make the fix that doesn't require tearing the dash apart. I have a '95 Z-71 and a '96 Suburban that both leak here. It drives me insane.

I pulled that foam tape out an siliconed on the inside an what I could reach on the outside of that joint. I removed the hood for better access, I put two coats of silicone on the inside an then siliconed that cover back over it. So far no leaks since an I didn't remove anything from the interior....

 

[carluvr]

Yes, removing the hood would definitely help. I thought about this, but I don't have the option. I ended up taking a big handful of silicone and smearing it on there as best I could. I just have a hard time getting my fat hands down in there to get it where it needs to be. Glad it's working for you!

 

[nathanb]

I know this thread is old but I wanted to say thank you to you guys. my truck was leaking into the cab just like the first post. I took my cowling off which is a fiberglass one and was a pain to get off. I put silicone under all the bolts for the windshield wipers. put silicone on the access panel and in the screw holes for the cowling then put it back together. it then rained hard on Saturday for about 6 hours. I went out to the truck when it stopped raining and there was no water in the truck. so now after a tube of silicone on the cowling area and the cab lights the truck is water tight. I just have to make sure when I have the windshield replaced it will stay water tight.

 

[carluvr]

This might help better explain the water leak issue:

https://www.youtube.com/watch?v=eQ_DN9eV5mk

 

[someotherguy]

Didn't read all 6 pages but this is THE cowl screw that allows water to leak into the interior; the others are irrelevant - trust me - the others will just let water into the cowl area itself which happens constantly anyway as it normally falls through the slats in the plastic cowl piece, and goes out the cowl side drains (the plastic ducts at each end of the firewall that have rubber flaps leading into the fenders) assuming they aren't clogged up.

Except for this one screw, because it is positioned directly over the mouth of the square walled-off area inside the cowl where the air feeds into the HVAC system from outside. If this one leaks, it drips right down into the HVAC system over the fresh air flap.

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Richard

 

[tscherbi]

I would take baby powder and pour it around where you think it may be leaking then take a air hose on the inside of the truck where you think the water is coming from and give it a good blow, you will see the powder fly, then repair accordingly. I do a lot of windshield replacements and have found this trick to work wonders for us.

 

[Coveman]

Thanks for the tip- I never would have suspected that one screw...

 

[AbramF_496]

I need this fixed ASAP my carpet sides are nasty and my backseat carpets get wet as well it's insane!!!!


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[inthechateau]

My 98 was leaking there and source was putty sealing fresh air vent under WS cowl. Was a pain to get the back side but it sealed it up.

 

[AbramF_496]

Didn't read all 6 pages but this is THE cowl screw that allows water to leak into the interior; the others are irrelevant - trust me - the others will just let water into the cowl area itself which happens constantly anyway as it normally falls through the slats in the plastic cowl piece, and goes out the cowl side drains (the plastic ducts at each end of the firewall that have rubber flaps leading into the fenders) assuming they aren't clogged up.

Except for this one screw, because it is positioned directly over the mouth of the square walled-off area inside the cowl where the air feeds into the HVAC system from outside. If this one leaks, it drips right down into the HVAC system over the fresh air flap.

You must be registered for see images attach

Richard

Took the two screws out on each side gonned some silicone in there with a small pointed file end. And screwed them back in home it works supposed to drizzle it's enough to get everything wet


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