Rain Water Leaks into Cab

[SEA-HAWKS]

So with my issue it was because their was a tiny hole in the gasket which surrounds the window. I took the cowl apart cleaned everything out including the vents along the the sides by where your feet are. My issue was resolved again by replacing the windshield gasket.

To keep debris out of your cowl LMC sells metal meshing that goes under the cowl which I put in and would highly recommend everyone else out there to do as well. It keeps debris not only out of your vent but you don't want dirt and other stuff collecting down there because it will eventually rot out your truck. I cleaned it out with water my hand and compressed air. It is a very cramped space so you may need a air wand.

As far as the flapper goes I would suspect that is where you get the air from for your heater, vent and air conditioning. I would recommend just replacing it or fixing it.

Hopefully this helps. This site from what I can tell is not super helpful about a lot of things but it isn't worth deactivating either. Best of Luck!

[Palf70Step]

More than likely you got spots around the side vents or the underside of the cowl that has rusted thru from glogged drains The drains come thru near the kick vents and out under the fenders, but that gets a lot of leaves/etc in there and can stop up the flow.

Far as cover up the cowl vent it would restrict the air flow some for the heat/defroster, but they would still work some, but you would be pulling in more engine compartment air instead of fresh air. Chances are it would not stop the leaks as there is may ways for water to get thru on that cowl panels besides those vents.

I'd pull your wiper arms, than take off the vent and clean/flust it out real good. also check the area around the side foot vents for leaves/dirt and bad seals. Look for rust spots. Taking our=t the rubber seal in those side vents will let a lot of air into the cab and water...especuially if the drains are clogged up.

[nitroscott]

You guy are great for taking the time to post an answer. I have been working on the truck and figured out what I am going to do, is put screen under the cowl vents with stainless screen from depot and hot glue it because the leaves and dirt that builds up will hold water and rust the truck. Second issue is the leaves and water coming in thru the floor vent. I am going to put sheet metal over the hole and screw it with self tappers and seal it with liquid nails which works good for seam sealing. No more leaks. I dont think I need outside air by my feet, if I do I will open the wing. Thanks again.

[swamp rat]

Originally Posted by nitroscott

Thanks for your response. My water and air is coming from the outside air intake hole under the cowl. Has anyone covered that hole and did that eliminate the problem?

Maybe you could post a pic of the hole your talking about and what side of the cab?

Here's a couple pic's of the side section of the cowl removed and another with the dash removed on the passenger side. This cab looked almost cancer free except a little on the floor boards, as soon as the heater was removed a different story came to light. looking at it you can see a lot of possible ways the water has attacked the cab, that seam and overlap is one of the biggest culprits to water getting in the cab but also look at the inside where the dash was removed the metal is rusted thru yet the window frame and gutters are solid.

Also the driver side so you can see how its put together.

[nitroscott]

Swamp Rat, Those pictures are everything that I was needing, thank you for them. I now realize that I can not seal the vents off from the outside. So I am going with the original plan of sealing them off from the inside to keep the leaves and water from getting into the cab. I dont think I need the inside lower vents anyways because the wing vents can put off some serious wind by themselves.
I really like your pictures, always wondered what the heck it looked like behind the fender. Thanks again.

[stsalvage]

Originally Posted by nitroscott

You guy are great for taking the time to post an answer. I have been working on the truck and figured out what I am going to do, is put screen under the cowl vents with stainless screen from depot and hot glue it because the leaves and dirt that builds up will hold water and rust the truck. Second issue is the leaves and water coming in thru the floor vent. I am going to put sheet metal over the hole and screw it with self tappers and seal it with liquid nails which works good for seam sealing. No more leaks. I dont think I need outside air by my feet, if I do I will open the wing. Thanks again.

Trust me you will want Air at your feet I drove my 1965 3/4 ton for 15 years and i loved opening my lower Cab vents.Unless your going to put a thick peace or fire proof under your truck or move your mufflers to the back of the bed you will have Heat I put a lot of padding at my feet still got Hot.Then Vents do so much to cool your feet off.

I take it you don't drive your truck a lot on the real hot days.Them vents do wonders to cool your truck down in side

[stsalvage]

this is one of the best post on this truck Site I take my hat off you you Sir for showing this one thing that I would not attempted to do to a truck With fear i could not be able to put it back together.Again Very much thank you for showing this too me

[Daner]

Originally Posted by nitroscott

Swamp Rat, Those pictures are everything that I was needing, thank you for them. I now realize that I can not seal the vents off from the outside. So I am going with the original plan of sealing them off from the inside to keep the leaves and water from getting into the cab. I dont think I need the inside lower vents anyways because the wing vents can put off some serious wind by themselves.
I really like your pictures, always wondered what the heck it looked like behind the fender. Thanks again.

If you cover up the cowl with screen you won't have any more trouble with leaves. Don't do anything with the vents but make sure the drains you can see in the pictures are clear. Take the cowl off then get the hose out to find your leak.

[MAC71]

This was my leak.

[swamp rat]

Looks like ya got a little fab work to do, the good news is it will all be hidden once the outer cowl is welded back in place. After you weld it up it would be a good idea to smear some seam sealer over all the welds before you paint it in case there is some pin holes you don't see after welding.

The other poster is correct about the intake mesh covers, i have added them to my truck as well, but i'll be damned if i can remember who i bought them thru, might try calling places like Brothers, Classic Heartbeat, Classic Parts, Eckler's, ect. and ask, i cant seem to search them up online right now. Mine is actually a sheet of thin aluminum that was fed thru a punch press, it cut the periphery with a thousand holes punched in it rather than a mesh screen

Another option is to find your own fine wire mesh and make one, one guy here did that and used a hot glue gun to attach it to the bottom of the cowl, don't know how it lasted tho.

If you look at the bottom of the vent cowl you'll see that it is open and the idea is to allow for water drainage, but i don't think Chevy thought about leaves or pine needles getting in there, i removed my vent doors vacuumed what i could then took a length of wire and fished it down thru thru bottom and flushed it with water to get them cleaned out.

[swamp rat]

Originally Posted by stsalvage

Trust me you will want Air at your feet I drove my 1965 3/4 ton for 15 years and i loved opening my lower Cab vents.Unless your going to put a thick peace or fire proof under your truck or move your mufflers to the back of the bed you will have Heat I put a lot of padding at my feet still got Hot.Then Vents do so much to cool your feet off.

I take it you don't drive your truck a lot on the real hot days.Them vents do wonders to cool your truck down in side

I agree.

[nitroscott]

I thought about it and with all of your all help and good advice I am going to keep the vents and not block them off. I did put the screen over the cowl. While I was at it I did my 83 cowl also. Check out the LEDs I put in the bed and the authentic 1972 license plates. Thanks

[nitroscott]

Here are the pictures...