Cowl reseal - 1986 F350
 

I'm sure I'm not the only one on here who has by now developed water leaks from the cowl area into the inside of the cab. It usually shows up as a soggy carpet. I will document what I did on my truck to fix the problem.

I had two areas, one seemed to be coming from over the brake pedal area and running down the inside of the firewall near the steering column, the other was over on the right side near the HVAC recirc inlet, but seemed to have a smaller leak that may have been there since the truck was built (more on that later).

I went down and talked to a good friend who owns the Hampton MAACO. He said If I would bring the truck down with the cowl grille removed he would see what it would take to reseal it. They have done a number of Mustangs for customers, but they involve cutting the grille off and welding it back on when done.

When I took the truck down, Dale looked at the caulking in the cowl well area, reached in and took a peeled up piece in his fingers and it came right up with no effort. He told me to go get some rubberized spray on undercoating from a parts store and remove the old dried out caulking and spray the undercoating in place of it.

Here is what I removed, notice that very little of it looks like it was still adhering to the metal.

Cowl reseal
 

Here are some pictures of the cowl area after removal of the petrified caulking. The last picture is the deflector on the right end above the HVAC fresh air inlet. The original caulking sealed the front (right side in picture) so water running that way was diverted away from the inlet.

Cowl reseal
 

I had cleaned and sprayed the area with a rust converting primer before I took the last set of pictures. After it sat for 24 hours, I started spraying the undercoating in. Here is the undercoated area. I had a hard time getting the undercoating all the way up in the area behind the booster. I finally took and old piece of vacuum tubing and held it right against the nozzle on the undercoating can so I could direct it right into the seam there. It took two tries to get that area to stay dry.

Cowl reseal
 

I finally had dry floor (carpet was removed before starting this) on the driver's side. I still had a trickle showing up from behind the kick panel on the passenger's side. I removed all the trim from that area and waited for the next monsoon. While it was pouring, I went out with a small flashlight and my little camera and found this: A small trail leading from the corner where several panels, firewall, toe board and side air box all come together. I had found evidence of this in a rusted weatherstrip flange, a hole in the bottom of the right front door and a matching hole in the side behind the weatherstrip.

Cowl reseal
 

Since I didn't want to do a stopgap seal it on the inside, I removed the dummy air vent cover that air conditioned trucks have so I could see into the air box. I then used my birthday present to take some pictures. The first one was an eye opener, it looks like there was never any caulking in that corner.

I pretty well had to spray the undercoating blind, then look at the results. I did the vertical seam just in case it was running in behind and down.

Added to the Chassis, Body, Trim and Exterior of the Sticky :)

Thank you sir. I figured it might be useful to others.

Great information Bill!!! Is there any paricular undercoating you used or recommed?

I had a bad leak also on a 86 ranger someone gave to me. It was also where the toe board/floorboard as it angles up in the passenger side behind the kickpanel, meets the metal behind the kickpanel, right in the corner seam.

I looked all over and took the fan and all that stuff out, and found no way to get to it, so I went ahead and took roof tar and smeared it in the corner from inside, and it stopped it believe or not. But I didn't think about the vent panel, though I am not sure the Rangers had it, I will have to look. My experience so far is that they are just mini versions of the larger trucks.

Cowl reseal
 

Ok, I took a picture of the two cans I used, here they are:

Bill,

I've had good luck with self leveling urethane sealant on horizontal seams.
1C-SL
http://usa.sika.com/content/usa/main...3039652160.png
This is a Sika product meant for things like expansion joints in concrete.

SuperSeal (makers of leak indicating dyes for automotive applications) have a product called 'Spray On Duct Tape'
I've used it for other things like sealing leaky flashings and gutters.
It seems to hold up well.

http://idqusa.com/prodimages/190-DT.jpg

Just some other possible options...

my guess would be that roofing tar is not to far off in composition than undercoating. Stays a little softer probably.

That's what it's made for...to keep water out, right? :)

Jim, that was mentioned, but the stuff I found was a body sealer and was a two part epoxy type.

The reason I wanted to seal it form the outside was to keep from having water trapped under the sealer and rusting it from the back like a Chevrolet fender.

Oh, I'm sure to seal it from the outside!

My truck's rain gutters and roof seams were leaking.
The self leveling stuff seemed thin enough to flow into any cracks and viscous enough to not just run right through.

I also had to clean, reseal, prime, and undercoat my cowl and insides. I used a tube of seam sealer that I bought at my local collision supply house. I had to use it in quite a few places around the body, some of which will eventually need to be painted. I had to get some good quality stuff that could be primed, sanded, and painted. I used a high quality 2-part epoxy primer to seal out the rust also. Then I sprayed some undercoat over everything as added protection.
Here are some pictures;
http://i774.photobucket.com/albums/y...2/100_5551.jpg

http://i774.photobucket.com/albums/y...2/100_5550.jpg

http://i774.photobucket.com/albums/y...2/100_5568.jpg

http://i774.photobucket.com/albums/y...2/100_5573.jpg

http://i774.photobucket.com/albums/y...2/100_5570.jpg

http://i774.photobucket.com/albums/y...2/100_5580.jpg


http://i774.photobucket.com/albums/y...2/100_5583.jpg