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I'm investigating leaks in my 1983 F350. I'm definitely replacing the cowl to hood weather-stripping, as it's hard and cracked badly. I took off the cowl vent cover and noted there was some kind of foam/insulation/stuff? on top of the cowl area...…..sort of on the front edge of the cowl area. I wasn't sure what it was for, possibly to channel water to the side drain areas? I was wondering if I should be putting something down in that area before I reinstall the cowl cover. Whatever is was, it was dried and basically, I could flake most of it off with my hand and a screwdriver (it basically turned to powder).
Also, what is the best way to get at the cowl drain areas; do I need to take the front fenders off?
Ok as you saw there are 2 cowl seals and they 2 different things.
The one you see when you open the hood and seals to the hood is for water so it will not drip down the motor / trany.
The other seal, foam type, that is between that outer part and inner seals off heat.
Remember the cowl pulls in fresh air. If that seal was not there it would be pulling in hot air from the engine bay area.
My 02 Durango does this, it has a seal but does not seal vary good from the factory so need to run AC year round.
As for the cowl drains.
I don't know if you can undo the inner fender liner to reach them as I had my fenders off.
What you are looking for we call "duck bill" as that is what it looks like. In the picture it is the black thing to the left and a little lower of the lower door hinge.
Now if you cant get to it from outside you can get to it from the inside if you remove the kick panels. If you have AC you will also have to remove the 4 screws holding that metal plate, and you have access to the drain.
You might be able at first to pull out hands full of crap then get in there with a vacuum cleaner to get the rest.
When I cleaned mine I used shop air to blow from the top down and bottom up till it was clean.
After it is clean look for any cracking seam sealer and reseal as needed. Some have used that spray sealer you see on TV to seal a door to the bottom of a boat.
They changed the nozzle for one you can use a plastic straw like with carb cleaner, this way they can point it where they need to seal.
They also did the same to paint the area, so what it you got runs as long as it is covered and will not rust.
Dave ----
I should note I have not put my truck back together yet, got to paint it.
But I will use a closed cell foam, it is like door weather striping, to seal mine.
Because that open stuff will turn to dust over time with heat and it can also hold water and that can cause rusting.
Dave ----
Glad I ran across this. I’ve run into similar issues on my ‘80 but it’s anatomy is a little different. I’ve cleaned out the duck bills and replaced the cowl to hood strip but it will still leak in the wash or with a good rain. I found the primary cause was a gap where the firewall meets the “fender bolsters?” (See picture, fuzz I borrowed your pic for demonstration purposes) the sealer in there almost looks like black jack roofing tar that’s dried out.
I don’t remember seeing any foam-type seal anywhere around the cowl? Would it have been along the hood edge? I know this is a little awry of the original post but thought any information pertaining might be useful
Glad I ran across this. I’ve run into similar issues on my ‘80 but it’s anatomy is a little different. I’ve cleaned out the duck bills and replaced the cowl to hood strip but it will still leak in the wash or with a good rain. I found the primary cause was a gap where the firewall meets the “fender bolsters?” (See picture, fuzz I borrowed your pic for demonstration purposes) the sealer in there almost looks like black jack roofing tar that’s dried out.
I don’t remember seeing any foam-type seal anywhere around the cowl? Would it have been along the hood edge? I know this is a little awry of the original post but thought any information pertaining might be useful
No problem on the picture.
Mine had dried / cracked sealer there also but I only remember to get to that area is remove the fenders.
As you can see my fenders were removed so was no issue to see and fix.
That foam seal in under the cowl cover that has the slots or the later ones with holes. Its glued to the under side of the cover, or is it the cowl on the truck? But it is under the cover.
There is also the same foam seal under the panel that access the wiper motor but the only time I would think this would need to be replaced is if you were to remove that panel.
Dave ----
The substance I'm talking about is under the slotted cowl cover, only visible when the cover is removed. It's on the cowl itself, directly in front of the large factory holes in the cowl. It appears there was more if it on the driver's side, although it may have worn away over time. It appears to have been some kind of foam. When you squeeze it with your fingers, it basically disintegrates into dust. It doesn't totally block anything because it was never adhered to the cowl cover. Looks like it was some kind of barrier, perhaps to keep water from going over the front edge of the cowl.
this was a great post with helpful pictures pertaining to this kinda work
im kinda wondering if the foam material you’re finding is more of a sound (squeak/rattle) insulation that the dealer maybe put in at some point. I found foam and felt all over the inner door panels and dash of my truck when I started pulling it apart
I'm thinking about putting a bead of non-expanding foam around the front of the cowl where that substance was, can't hurt, I guess. :-)
Um, actually it might. Are you talking about construction grade stuff from a pressurized can? Most types of foam sealer aren't designed for continuous water contact. If rainwater can contact this area, especially if it sits there, the foam may soak up the water and hold it against the sheet metal. The metal will then rust away under the foam. An automotive body seam sealer is going to be far better for such an application.
Can you please post a picture of the area in question? I'm not fully following where this problem area is located. Will water collect there or will it run off?
10-19-2018, 10:54 PM
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