cab leak

This may seem really dumb but i figured id give it a shot. My '83 F-250 has a pretty bad leak that is right up under the drivers feet , coming from somewhere behind the instruments it seems. The windshield seal seems to be decent from what i can see with a flashlight, and the way it is sealed it doesn't seem like water could get in from there. The water runs on top of the rubber floor mat just above the bright switch, and it also completely soaks the drivers side floor pan pad underneath the rubber, and it's causing my floor to rust out prematurely.

I currently go to Texas A&M and due to a super busy schedule and lack of any place to work on a vehicle i haven't been able to find the thing, and was wondering if anyone else had experienced a bad cab leak on an '80 and up F series truck in the same place and could point me in the right direction. Anybody heard of a cowl cracking or a seam up there losing its glue or something allowing water in?

I was just thinking that maybe if you have somebody spray water in the area where it leaks an you could get a light up under the switch an maybe could see where its actually leaking maybe give you an idea. Anybody else have any ideas guys. Hope you figure it out an get her fixed. Good Luck.

does it leak when it rains when parked or only when you drive in the rain.

Thanks for the replies. Yes it does leak in park, in fact, it almost seems that the leak is worse when its parked than when its driving.

When I get a chance i guess ill try getting a friend to dump buckets of water directly in the cowl and see if I cannot find anything, the last couple of days I've had the floor mat pulled back so the thing can dry out... smells terrible. I'm just hoping I don't have to pull the cowl and fender off and start regluing stuff.

Dave sounds like a plan. Finding these leaks can drive a guy nuts. Been there done that. With two guys it really helps. Keep us posted on what you find out. Good Luck

Does it have cab lights?
it could be leaking in the cab and running down the pillar (behind the plastic) and showing up where it is/???

I'm going out on a limb.
If i were betting it'd be through the windshield.

Found 2 leaks.

Got a little time today and the sun came out so i pulled up my floor mat and tore out all the insulation on the drivers side. Next, I poured a half gallon of water in the cowling and on the windshield wiper and noticed a river pouring in the floorpan not from up high, but the damn E brake cable going through the floorpan right next to the firewall!

It would seem that whatever seal originally went around the cable is now gone, and adhesion was allowing the water to wrap under the bottom of the firewall and onto the cable where it found it's way into my cab. I'll probably just put a giant blob of silicone on the cable and seal it for good.

The next leak I noticed was barely a trickle, but runs down the seam where the metal behind the kick plate meets the firewall, up near the top (at the bottom of the cowl). Seems my beating on this truck and the hot weather down here has caused the sealing from the factory to crack and allow some water in.

I'm just glad it looks like I will be able to fix this thing without tearing off the cowl cover and fender, but the mildew smell probably isn't going away any time soon, or the rust that has developed on the floorpan. I'll probably just dump a ton of chem-prime on the floor pan and try to convert some of the rust to zinc. Either way, any of you with an 80-96 pickup ought to check that cable seal, it will allow alot of water in if its gone.

Well its good you've found the leaks. thats half the battle. :D

Or check by removing the chrome windscreen flashing worst part bout that if there rust starting any where that's where it ll be. If the windscreen s been replaced and the rubber seal wasn't replaced they ve used goo instead you end up 1-3 inch gap that will fill with dust insects an leaves (I know it sounds like a house gutter) it might rust through as there s no where for the water to escape When I replaced the Windscreen in mine I noticed this I had no rust but put a bit of fish oil round it now I strip the chrome every few months an clean it out by the way they little clips are a bugger and be careful of little studs they click on to I ll find the photo s to explain what I mean tomorrow