Seam Sealer advice for leak in cowl seam.

[HWYCRZR]

Looking for some advice from the seasoned body guys on the correct placement of seam sealer in the cowl drain area of my’68 Polara

This weekend at Mopar’s in the park we had a good overnight rain and when I came out of the hotel Saturday morning my passenger carpet was wet. At first I thought my windshield gasket was leaking, but when I got home I removed my side cowl vent covers and peeled the carpet back. Then I took the garden hose and sprayed the windows seams up and down. Nothing. Then I put the spray over my cowl inlet on my hood and sure enough I found a small hole up in the corner of the cowl where there is seam sealer. It’s in the area that kind of forms a pocket which slows the water down enough to leak through.
If I use seam sealer to seal it can I do it on the inside, or should I really remove my top cowl inlet and seal it from the outside? Or is there an alternative sealer I should be using?

Thanks for the advice.

 

[65sporty]

Now I am not a seasoned body man so take this with a grain of salt. I had a customer with a 90 Mustang GT, he had hit multiple deer over the years and he had a leak much like you do. I pulled the dash and cowl and seam sealed the leaks I found, it had some wrinkles from multiple deer hits.

 

[HWYCRZR]

I took the cowl panel off and it’s in a place that you can’t reach from the outside. So it looks like I need to try and seal from the inside.

 

['69FuryIIIConvertible]

Clean it out first, then apply SEM seam sealer, its DTM and doesn't shrink.

 

[413]

Remove the sealer in the leak area and a few inches beyond on both sides.
Clean up any rust.
Paint with catalyzed paint
Seam seal it.

Don't use silicone for engines.

 

[73Coupe]

I took the cowl panel off and it’s in a place that you can’t reach from the outside. So it looks like I need to try and seal from the inside.

Do you have any pics of the other side, after you took off the panel? Does the exterior cowl panel w/ vent holes come off on slabs?

From the pics above, it looks like the entry point is where the angled floor board meets the vertical firewall

It may be leaking in one place, then running to another location where it's entering the cab.

I recently used Evercoat "brushable seam sealer" available from Eastwood inside my cowl.

 

[HWYCRZR]

Here are some outside pictures

 

[HWYCRZR]

If I pulled my vent off the inside I may be able to reach around.

 

[HWYCRZR]

And took off my heater intake. Now I can get to it now. Right in that corner is where I think it’s coming from. It will be difficult to remove the old.

 

[Rainy Day]

Looks like the old seam sealer shrunk back and exposed a few small pin holes..

 

[HWYCRZR]

Yes, I need to clean it up and then re-apply. It should fix my leak issues in a down pour or steady rain. That corner is kind of a low spot as well. At least I can kind of get to it now to clean up some of the old bead before applying new.
Still not direct access. My knuckles are a little raw trying to get into there.
I need to make sure there is a nice transition around the corner so I don't trap any water in there.

 

[HWYCRZR]

Well I am glad that I wrapped everything in plastic. Seam sealer sucks. I doesn’t help that the area I need to get to the gun doesn’t fit. I thought I would be smart and add an extension hose to “easily” apply it to where I needed it. Good in theory until the extension hose pops off. Any way I got a glob down where I needed it and massaged it to where I needed it with my nitrile gloves. I attacked it from the outside and from the inside. Not the prettiest job, but I got it where I needed it. I don’t dare take a picture of it until it is fully dry as my phone is likely to get gummed up.