73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Body, Glass & Paint => Topic started by: jaredts on December 13, 2009, 06:54:58 pm
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I wonder what would cause water to leak into the floorboard near the accelerator pedal from the firewall? The insulation is wet and I realize I have to rip into this a little, but it even happens after a light rain. Any thoughts?
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when that happened to me it was a dried out windshield seal, had a heck of a time getting it all taken care of, but that was the biggest problem i had for water.
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Plugged windshield weep holes, rusty windshield frame, and most common, rusted out cowl.
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Where are the windshield weep holes? Sounds like I need to pull the cowl panel off and see whats going on from that side.
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weeps are Under the windshield gasket.
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Thanks for the help. Gotta dig into this very soon--I just finished the cab repair on this side of the truck, and now I see why it was so much worse than the passenger side. Looks like a river was running under the carpet and rusting out everything where the floor meets the weatherstrip lip. All fixed and pretty now, but don't want this leak to ruin it all.
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Check this post:
http://forum.73-87chevytrucks.com/smforum/index.php?topic=12521.0
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Can't thank you enough, Chris! The pics in that post will be very helpful. I'm going to get into this right away, but I am a little worried. I'm not sure what kind of rust to expect. All I know is its going to be bad!!! I'm having a blast working on my '83 Silverado, but next time I buy a project truck I will be much more picky about a somewhat rust free body. I love working on cars/trucks, but grinding and eating rust is getting a little old.
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I think I've found my leak. Under the cowl panel the firewall has seam sealer on it that has cracked and is starting to rust. The rust doesn't look too bad, yet. Problem is I don't know how to get in there and what exactly to do. Access is limited. Here's a pic. When this seam goes, water will run into the floorboard, right?
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When that seams goes, you will have a waterfall down the firewall.
I would wire brush it and remove any scale, do an inspection and see how bad it is. If it is just the seam seal that is gone, coat it with chassis saver or POR15 and reseal it. If it rusts you are going to have to make patches for it...
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get your leaks fixed,,,on my 74 there are several grommets located on the firewall that were deteriorated......same thing..maybe
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Update: I got this fixed--for now. I've only got two or three hours in it, and it turned out pretty nice. I peeled up all the old seam sealer and wire brushed the seam. This exposed a few pin holes and one that's nearly 1/4" diameter. I think down the road this is going to need more attention (weld patches). I don't remember the name, but I bought an SEM product that I thought was similar to chassis saver or por-15. Nope--it turned out to be a cheesy rust converter product that you can paint over. After trying it on some test pieces I really wasn't happy with it so I sprayed the seam with rust-oleum rust reformer (I know, rust-oleum is the devil). I then went over that with a heavy bead of seam sealer that covered well beyond my small rust holes. I found that a piece of shoe molding works great for smoothing out a nice wide bead. The only problem is that I cannot reach all the way out to the edges of the seam to the extreme left and right sides of the truck. Those areas seem impossible to get to. I'd take some pics but its covered in snow right now. Maybe in a few days.
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This is the Weep hole under the windshield gasket
(http://i160.photobucket.com/albums/t195/wes2880/78%20C20%20Rebuild%20Stuff/Ready%20for%20the%20body%20shop/GEDC0016.jpg)
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So that's what the weep holes are supposed to look like. Mother nature thought mine should be like 10" long and 1/4" wide ;D
(for the record, I did patch them and drill a hole for a new weeper.)
jaredts, can you reach down with your fingers? Maybe smear a little seam sealer to try to tie into the old stuff.
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My leak was the seam under the cowl panel (under the plastic screen). To the left and right of the truck there appears to be no way to access it except through the holes under the plastic screen. I was able to reach about 8 or 10" back with the shoe molding and spread seam sealer, but just before the seam curves down I can see a few inches that I could not reach no matter how hard I tried. The only way I can see to get to it would be to remove the fender and cut a hole in the cowl (not in my plans). This seems to be a common repair, has anyone else found a way to do this?
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Just a pic. for prosperity. A bit sloppy, but the seam itself is nice. Its hard to work through the small openings. Never could find a way to get it sealed all the way out to where the seam curves down the sides of the truck, but its a lot better than it was. At least the waterfall down the firewall is gone (no leaks)! http://s970.photobucket.com/albums/ae188/jaredts/83%20silverado%20cab%20repair/83%20silverado%20cowl%20seam%20repair/?action=view¤t=CABCOWL001.jpg