Help with a water leak.

[Dutch Rutter]

Hey everyone,

I've been having an on going and very small yet annoying water leak during heavy rains. The water leak at first appeared to be coming from behind the center of the dash. After further investigation I now believe it to be coming from the inside of the HVAC tube (AC truck so I have the large hard plastic ducting). AC is not hooked up but all of the lines are intact.

Before finding this I cleaned the cowl drains and checked everything out there and besides a large paint peel in the cowl itself on the passenger side I didn't see any other reason to suspect this to be the problem.

Any ideas on where this little bugger might be or how to go about fixing it?

 

[1987 GMC Jimmy]

This came up a month ago...

http://www.gmsquarebody.com/threads...-front-floor-when-it-rains.20492/#post-381269

Also, you may want to try simulating the conditions with a garden hose. I've dealt with leaks before (not in my square thankfully), and that's what I did.

 

[Dutch Rutter]

Should have also mentioned, last month had the windshield and gasket replaced (old windshield was busted up). When they were replacing it they said they did not see any signs of a leak near the windshield. However, It is still under warranty so I have no problem taking it back to them.

I have not tried the garden hose trick yet but i think its probably time to do so this weekend. Its strange to me because its not a very large leak. During the 30m drive to work this morning in hard rain I only had 5-6 drops of water on the passenger side floor board under the HVAC ducting and 2 on the center hump also under the ducting. (hence why I was thinking it was coming from there)

Honestly I'm getting a bit lost in tracking it down. But I think the hose will help pin point it a bit more.

Thanks for the help! I'll make sure to post back more as I dig into it.

 

[1987 GMC Jimmy]

I know you said it was only when it rains, but is your heater core okay?

 

[Honky Kong jr]

Go to a windshield shop and have them pump some liquid butel behind the windshield gasket.

 

[Dutch Rutter]

Heater core seems alright. I mean heater works great, and it doesn't spit out any water when turned on, the flaps are a little noisy at times, kinda like a vacuum-ish sound when changing the vent selection. I do usually always have the defrost on would it be possible that the windshield leaks into the open vents and then runs to the lowest point in the ducting?

If the hose test results in a leak around the windshield I'll take it back to the place that put it in and have them do the butel treatment. I also read something about a weep hole near the windshield being plugged or rusted would this be something to check out?

 

[Honky Kong jr]

Heater core seems alright. I mean heater works great, and it doesn't spit out any water when turned on, the flaps are a little noisy at times, kinda like a vacuum-ish sound when changing the vent selection. I do usually always have the defrost on would it be possible that the windshield leaks into the open vents and then runs to the lowest point in the ducting?

If the hose test results in a leak around the windshield I'll take it back to the place that put it in and have them do the butel treatment. I also read something about a weep hole near the windshield being plugged or rusted would this be something to check out?

You can also sprinkle baby powder around the outside of the windshield and blow compressed air at the seal from the inside. You will see where the leak is faster then wetting it down.

 

[Dutch Rutter]

That is a great idea!

Thanks.

 

[Honky Kong jr]

That is a great idea!

Thanks.

That’s how I did it at the dealership.

 

[Dutch Rutter]

Alrighty. I started with spraying around the AC box in the engine compartment found a small hole with a wire ran through it just under the heating box. filled that. no more leak there.

Then ran water down the cowl. No leak to be seen.

Then Ran water over the windshield and door. no leaks from the door but I then found my annoying little bastard leak. I snapped a picture of is. might be kinda hard to see.
This is right behind the glovebox coming down between two pieces of steel that I think are parts of the dash.
Would this be coming from the windshield seal or could it be a body seam? other then this spot I did not see any other evidence of a leak, but I also did not pull my dash pad off. (i'll go do that now)

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Edit: Never mind can visually see it between the dash pad and windshield that the water is coming from it on the side as well as a few other spots. I can see water drip from the spot pictured as well as running down the passenger side of the glove box and down my kick panel. Will be Calling the glass company to get this fixed.

 

[CSFJ]

Good to hear you got it tracked down. I hated chasing leaks in my dealership days.

 

[Dutch Rutter]

I bet.
I can only imagine how terrible it would have been if I had a suburban way too many places for leaks. or trying to find leaks in a motor home.
Thanks to you guys for all the help though. I would have still been chasing my tail trying to find this thing. Hopefully I'll get it into them and wont have any more problems after its all done. Kinda disappointed in their work already, after they replaced the windshield I had to re-seat my dash pad. We will see if it goes better this time.

 

[Honky Kong jr]

Good to hear you got it tracked down. I hated chasing leaks in my dealership days.

Come on, only thing better then water leaks was rattles grrrr

 

[CSFJ]

After I would get done swearing at the advisor who brought it, I would usually tell them that the only time a water leak is a problem, is if you're on a boat.

 

[CSFJ]

You're right about the rattles though. I would bet that 90% of them were caused by owner modification, or simply the owners **** they couldn't be bothered to take out of the car since they were too busy bitching about a rattle.