Installing inner cowl
 

As I get ready to install the complete inner cowl (this so far has been a learning experience), I have come across a couple of questions. After I get my plug welds done and the piece installed, do I need to or at least should I add seam sealer along the top edge? I don’t recall there being any from the factory, but it could be a reason they had rust in that area. Anyone else have experience with this repair and suggestions or thoughts?

Re: Installing inner cowl
 

I would use some in that area. It would be cheap insurance against leaks.

LockDoc

Re: Installing inner cowl
 

Thanks Leon! Bought some 3M heavy bodied sealer as I will be doing the drip rails too before we get rain. Figured I’d just stock up!

Re: Installing inner cowl
 

That should work.

LockDoc

Re: Installing inner cowl
 

Seal all the seams. And when you think your good to go, go over it again . I used single stage polyurethane on my cowl and brushed it in good and used the 3m high build self leveling on the 68s drip rail

Re: Installing inner cowl
 

I am trying to understand the sealing process for my cowl leaks on both sides. The main leaks are where the inner cowl meets the A pillar. I have cut an opening in the upper cowl so that I can get to this area. It does appear there was factory seam sealer there that has failed. I am guessing the issue was the "diverter" probably got clogged with leaves/debris 30 years ago keeping the area wet and funky. One of the leaks is at the joint of inner cowl, A pillar, and "diverter".
My question while contemplating the mess under my dash was what about the firewall to inner cowl? I don't see any evidence of seam sealer across this long seam. However, it appears obvious that it needs to be sealed.
What say you experts?

Re: Installing inner cowl
 

My answer would be the same as I recommended in post #2...:)

LockDoc

Re: Installing inner cowl
 

I am no expert, yet with a leaking window covered by a tarp I can tell you this. If you plan to repair this area PROPERLY it is time to tear the truck apart and do a complete cab repair to get it fixed right the first time. I have seen many pictures of failures in cab repair.

Re: Installing inner cowl
 

Respect if you are doing inner cowl. That's a job.

Just so you know, the Loctite PL Roof and Flashing (Black polyurethane from Home Depot), works well for this application. Costs $8 a tube and is typically on the shelf.....

Re: Installing inner cowl
 

You could also use panel bond and it will attach it and seal it all at one time

Re: Installing inner cowl
 

I went to town with the 3M panel adhesive all over my weld areas in inner/outer cowl area. Didn't use the self leveling since it is really runny while setting up. That stuff did work like a champ on the drip rail, though.