Holes and Rust

[Droff]

Looking for some advice before I take a direction on any kind of repair here. I’ve got a ’68 ¾ ton GMC and had a bad master cylinder leaking fluid into the cab, under the carpet. Once I R&R’d the MC, I decided to pull the carpet and see if there was any damage underneath.

Once I removed the sills and the carpet, I kind of moved the weatherstrip as well and found a bit of a mess. It’s not from brake fluid. The pics are the driver’s side where the weatherstrip attaches and the channel that is to the inside of it. Obviously, some water is getting in, migrating to this spot and sitting there. Both sides of the truck are this way. I should be able to see where the water is coming from a bit easier with the interior out now.

To me, it looks like my rocker panels are good, at least the outside, not sure entirely on top though, other than what I can see. There is some bubbling underneath where the door sits when closed. I don’t want to start tearing my truck apart right now, just want to get it to more of a daily driver state, which is suspension and brake work. This looks bad and I’m not so sure I want to leave it as is until I get around to doing all body repairs on the truck, but whatever I can do needs to be manageable.

I’m not a body guy but not afraid to weld and give this a shot if that’s a path to go. Can this area be cut out, cleaned up and replaced or do I need to replace a certain section – floorpan or rocker?
Thanks.

[toiletbowl54]

yes it can be repaired. Go to Top Banana web site and look at the repair panels they offer. Some of the vendors on this site may also offer them, like gmcpaul

[franken]

Normal rust that they all have/had. Inner and outer rockers, probably cab corners, plus some bits you can't see yet. Run water on the roof and see if it comes in the cab--its common for the seam sealer in the gutters to crack and leak.

[GASoline71]

Once you cut away the outer rocker you'll see how bas it is. Be prepared for it to be worse on the inside then it looks on the outside. The inner rocker and part of the floor will probably be shot along with cab supports and the lower part of the A-pillar and the kick panel. Rear cab support and rear pillar might be bad too. They all rust out like this. Most of the water comes in from the cowl and also from the roof at the top of the A-pillar.

Looks to me like there was already a piece of floor replaced at one point. After 40+ years who know what's been done...

Gary

[In The Ten Ring]

My cab is just as bad, but you can't see for all the 1990 bondo!

I have a fist-sized hole behind my seat.

[Tiger Joe]

I'm betting there is water leaking in from the cowl area. I see rot making its way up the kick panel area.

that's certainly not a difficult repair, but it takes time to do correctly. looks like part of the floor may have been patched already at some point?

I see kick panel, floor, rocker, probably inner and outer rocker. and some of the door pillar there.

[Droff]

It does appear that a part of the floor was patched at one time, pax and driver. I'm assuming the wavy look is seam sealer with rust bubbled underneath of it(?). I scraped some of it off, it was kind of rubbery... and rusty.

I want to fix this correctly but the responses seem to lean toward much more metal repair than what I had in mind for right now. Inner/outer rocker, cab supports, kick panel, floor, A-pillar.... I don't want to ignore it, just don't have time in my schedule right now for that much. I NEED to get my suspension and brakes squared away (working on a little at a time) and then I have other projects that require attention.

The cab overall is solid, I won't be stepping through the floor or anything like that, doors close solid. The biggest issue is what is in the pics, which looks pretty rough. Anything I can do for a kind of 'temp fix' for a while?

I looked in the cab yesterday and saw some water in this area but couldn't tell where it came from, I did look under the dash and there wasn't anything dripping or running from there. I'll check into the cowl as well as the drip rails. The drip rails have some bubbling going on too, so that's a good possibility.

Thanks for the info.

[ChaseBBC]

Currently repairing the same issues on my cab. Don't have much time either so I just do "one piece at a time" - johnny cash. Not gonna lie, it takes patience, but im almost done. My advice is to order all your parts (lower A-pilar, rockers, kick panels, and a lil extra sheet metal first. Then dive into it. My sheet metal work has defiantly improved since I first started!

[Droff]

Originally Posted by ChaseBBC

Currently repairing the same issues on my cab.... just do "one piece at a time"

That would be the plan once I get to the point of having the truck sit for a good while and doing the metal work. Just not ready to have it in a non-driveable condition like that yet.

[HO455]

Originally Posted by Droff

It does appear that a part of the floor was patched at one time, pax and driver. I'm assuming the wavy look is seam sealer with rust bubbled underneath of it(?). I scraped some of it off, it was kind of rubbery... and rusty.

I want to fix this correctly but the responses seem to lean toward much more metal repair than what I had in mind for right now. Inner/outer rocker, cab supports, kick panel, floor, A-pillar.... I don't want to ignore it, just don't have time in my schedule right now for that much. I NEED to get my suspension and brakes squared away (working on a little at a time) and then I have other projects that require attention.

The cab overall is solid, I won't be stepping through the floor or anything like that, doors close solid. The biggest issue is what is in the pics, which looks pretty rough. Anything I can do for a kind of 'temp fix' for a while?

I looked in the cab yesterday and saw some water in this area but couldn't tell where it came from, I did look under the dash and there wasn't anything dripping or running from there. I'll check into the cowl as well as the drip rails. The drip rails have some bubbling going on too, so that's a good possibility.

Thanks for the info.

If i didn't have time for the repairs I would spend half a day cleaning it up and then apply Rust Mort or Ospho and put a coat of paint on it. Then seal the holes with some Tiger's Hair or seam sealer and a second coat of paint. Not permanent but it will stop or slow the rust and help keep water out. Plus it won't be difficult to remove when you have the time to replace the sheet metal. Por15 is an other option but a bit expensive for a temporary fix.

[Droff]

Originally Posted by HO455

If i didn't have time for the repairs I would spend half a day cleaning it up and then apply Rust Mort or Ospho and put a coat of paint on it. Then seal the holes with some Tiger's Hair or seam sealer and a second coat of paint. Not permanent but it will stop or slow the rust and help keep water out. Plus it won't be difficult to remove when you have the time to replace the sheet metal. Por15 is an other option but a bit expensive for a temporary fix.

That's sounds like a quicker option, wasn't sure what else I could do other than metal replacement. Hadn't thought of Ospho. Thanks.

[Droff]

I've started cleaning things up a little and tried to find the water entry points. I couldn't see anything com in from the drip rails so I ran the hose over the lower part of the windshield and cowl area.
I found 2 places where I could see some water, but not sure what's on the back side. The first is a drip from what looks like maybe the wiper motor area? It's kind of right above the gas pedal area.
Not sure how to get to this one, suggestions?





The other is more like a run, coming in just above the toe board/kick panel seam, where there is a slight bend. There's a hole there, I just don't think it's coming in the hole, more like seeping in under the adhesive (seam sealer?)
I don't know what's on the back side of this either, any way to get access without destruction?



Thanks.

[Droff]

I removed the cowl and did some more water testing. It looks like the seal/gasket around the wiper motor hole is pretty much gone. I didn't do a wet test there but I'd say that's a pretty good place to start for that leak.

The other leak in the corner is a bit more unknown. I ran some water over the heater blower motor area and water started leaking into the cab, but not from the heater box area under the dash, it was still from in the corner. So from the inside, it doesn't look like it's getting in through the blower motor area.

Any thoughts to what would be a possible entry point farther down the side of the cab? I'm not too hip on pulling the fender off right yet.

Thanks.

[HO455]

Here is a link to a thread with good pictures of the common rust areas. Hopefully this will give some insight on where your leaks are. Be warned there some graphic photos of rust. And for more links search for "cowl rust"

http://67-72chevytrucks.com/vboard/s...d.php?t=721974

[Droff]

I've got a few things squared away on the floor rust, I'll add some pics later. I would like to get some of the air flow blocked off in a few areas, which would include the firewall, kick panels and the floor.

I found two good sized holes, not quite golf ball size, on either side of the tunnel. Pretty easy to spot in the pic.
Any ideas on why they would be there?
If no good reason, I plan on welding some metal over them and then sealing them if that wouldn't cause some unknown issue on my part.
Thanks.

[Grandpas 72]

Delete posting

[Droff]

C'mon Grandpa, you're killing my thread Mojo....

[Grandpas 72]

Sorry Droff. I am new to this forum thing. I will remove my post and start a new thread😁