Hey guys, as the title says I got a good one. When I was doing the ZF swap on my 95, I had to take up the larger shifter opening panel and pulled the carpet up to do so. I noticed the carpet on the driver side was wet and figured I would look into it when the swap was done.
I figured I would run some water over the cab and take a peek inside. I had the hose dumping water into the cowl panel and by the time I got into the cab to look, I had a good stream of water flowing down my floor by the emergency brake. Closer examination showed it running down the inside of the fire wall up by the ecm and two other wiring connectors. It seemed to be coming from the far left side behind that large dash mount casting that also serves as the e brake mount.
I guess my next mission is to pull the cowl panel to do some sealing. Anyone have any input as to what I am looking at removing to gain access so I can possibly seal it up again? My guess is windshield trim and some screws at the rear hood edge. Thanks.

 

Mine leaks there too. It's a rust hole in the cowl on an otherwise (mostly) rust free truck. Truck's been in FL it's entire life as far as I know, and the only rust besides that hole is the drip rails, surface rust on top of the cab, and a rotten spot in the pass. side door jamb. To fix it right I think I'll have to pull the dash and the cowl, not too bad just time consuming.

 

Check the seam sealer between the cowl and firewall. Check all along the edge down in behind the fender. Look for cracking and or separation. If you see any rustnstainsnthat a good place to start.

 

Your leak sounds like my leak.

Go here, scroll about 1/4 way down, to "September 3 & 4/11".

My floor has been dry for two years now.

 

Well, I was able to reach up and clean out both drains. The driver side had some dirt and crud but no rust while the passenger side was dry and clean. Good post Bronco Bouy on your fix. Any reason you used urethane instead of seam sealer? I hope I can fix my 95 the same way. The next generation has a serious dash mount parking brake casting preventing me from accessing the area outboard of the ecm. It almost seems easier to take the fender off and cut an access panel in from the outside to do a patch if I cant get down from the cowl top side.

 

Thanks. I used urethane because I had a tube on the shelf. It's a good strong adhesive, so I use it on all kinds of projects.

 

There's a good chance you'll be able to seal the leak fro the outside in. I would try that first.

 

I have a small leak on the passenger side, definitely have to look into fixing that crack.

 

Even thought there is a hole there for water to coming in, you might be able to drastically reduce the amount coming in by just cleaning the cowl and drain.