Large water leaks in cab-both driver and passenger side

Hello all.

I'll have to manually check this as things go, as I have a gmail account and it's a bit wonky. But here goes:


Over the winter time I noted I was getting quite the iceberg on my passenger side floorboard. We're talking about 2" of solid ice. When ever it thawed? The water drained into the cab big time.


Now it's all warm and cozy (Okay, if you consider 60 deg's cozy....at least it's not snowing) And we are getting rain.

The passenger floor board is drenched. The drivers side is also loaded with water. (about 1/2 as much as the passenger side) I can safely say it's not coming from the top of the window or the sides down the pillers. (That's because we've had the pillar covers removed and it's dry as a popcorn fart. And for the top of the window? The headliner is now a 'custom' one and we can see the metal to window contact, so that's dry.

My gut feeling is that it's likely something in the cowl area has rusted, or the drain tube is clogged and that caused rust...seal damage, etc...

I didn't see much online for repair photos or any real listed DYI items.

My plan (due to not having much to go on) Was to exchange out the damaged dash (more cracks then I can count...) And while the dash was out? See if I can locate where the leak is coming from. When I was pulling the dash from the truck at the P&P yard--I noted the dash only gets you about 1/2 home. The air duct work and other assorted bits in the way make the job look a lot larger then I expected. The newer dash is still going in. It's the same color and in pretty solid shape with no cracks.

Plans at this point would be to take the truck up to the families place and use the garden hose to see where this is leaking 100% for sure. If it turns out to be the cowl area, seal or rust.... Is there a good way to access it for the repairs? I've seen people talk about pulling fenders, etc... I have the feeling I'll need to have the area in the cowl open enough so I can reapply any sealant or do rust repair.

Any hints, photos, etc...would be fantastic.

Thanks!!

S-

Go with your current plan. Pull dash, hose down. It may well be the cowl is rusted out. You might get lucky though, I had a pretty good leak in my cab a while ago and when I pulled the dash it was just a bad seal on the wiper access patch. Mine only leaked when driving into the rain though.

Wondering about the idea about the fenders for cowl access? I've never had to pull the fenders off this thing.

The dash comes out for replacement in a few days (taking a few days off from work to get this sealed up)

Now is the time for the planning....Just had a great time pulling the dash from the salvage yard truck.... That was a lot to learn in a short time.

The earlier years with the slots in front of the windshield were notorious for leaves getting in the cowl area and rotting out the metal. The cowl is spot welded to the cab, unlike a full size, so a good spot weld cutter and removing the glass is the "right" way to fix any rot. I've seen one thread where the owner cit a few spots by the hood and lifted the cowl enough to fix his. Bit it really depends. There are some leatherette patches under the fender that you might get something in to apply some caulking. There is also some access panels from the front under the hood.

Sent from my XT1032

My 87 had a problem like this. It was the body panel seams, just below the bottom corners of the windshield. I took the windshield trim off, cleaned out the old seam sealer with some small, long bits on a dremel tool, cleaned it with rubbing alcohol and re-sealed it. No leaks after that.

Well, this is the '89 we are talking about. It's got the updated 'mesh' design. Time to get out the garden hose once the dash is out and find out for sure.

I've got the weekend off to tackle this one, pulling the dash at the yard took a while, but that should make pulling it on mine that much faster.

S-

Sounds like quite a bit of water...almost too much for a simple leak. Unless you've had way more rain/snow than other places...

It could be any of the above responses so be prepared for the worst case scenario...I'd suggest a few cans of that rust converter and maybe something to patch holes with...I had my 88 dash out last summer and found the metal around the inside corners of the cab where the windshield meets the dash/cowl was starting to rust out on the driver side and had penetrated on the passenger side...

It may be hard to see in this image but you get the general idea...

http://i1179.photobucket.com/albums/x399/akwarian8/Truck%20Build/RustDriversidebelowwindshield_zps37c6080f.jpg

The access for the cowl area at the sides of the truck are miniscule but you can get a hose in (or aim it into the hole) to wash it down...at one point I was tempted to simply cut out the metal where the slots/holes go and saturate the area with rust converter and try to patch holes from outside as well as the inside...but I decided that would be too much work to fix again and I don't have welding tools...

Well...

Dash is out. New dash is prepped and ready to be installed.

That's the good news.


Found the leak. At this point it might make a lot more sense to remove the R fender the rest of the way to seal it. The leak is a large one, looks like the rubber sealant used on the seam gave out. I removed the fender enough to peal back the 'side doggy door' they use for water drainage. Nice rust hole and left over rubber sealant greeted me.

The only way to fix it inside the cab is to remove all the heater ducts and heater box. Sense the leak is right within fingers reach via the 'doggy drain hole' I think that's the best bet. Everyone in my area keeps saying use that new spray on heavy duty sealer. So I'll probably give that a shot. If it fails, removing that fender is pretty simple when compared to pulling the dash.

And yes, it's a good size leak/hole. Thankfully it's right where I can get to it via that fender.

S-

You might be able to make that doggy door a bit bigger but it would be close to losing a bit of the integrity of that area...I'd be interested in seeing that if you have time to document it...although I know what that is like with my own repairs...I get going on it and by the time I realize I should have taken some pics it's too late...

I used some aluminum tape on one section that was almost impossible to fix otherwise. it is super strong and I coated the area with rust converter then painted it with rust paint...once it dried I put the aluminum tape over it and hope it lasts...lol

That's usually the end of the cab if you aren't able to fix it...for someone else to do it would cost a small fortune, but it would save the cab for decades...

Mark_88 said:

You might be able to make that doggy door a bit bigger but it would be close to losing a bit of the integrity of that area...I'd be interested in seeing that if you have time to document it...although I know what that is like with my own repairs...I get going on it and by the time I realize I should have taken some pics it's too late...

I used some aluminum tape on one section that was almost impossible to fix otherwise. it is super strong and I coated the area with rust converter then painted it with rust paint...once it dried I put the aluminum tape over it and hope it lasts...lol

That's usually the end of the cab if you aren't able to fix it...for someone else to do it would cost a small fortune, but it would save the cab for decades...

Click to expand...

Rest of the cab is still in decent shape. Kinda gets a bit frustrating when there's not a lot of rust--but the area that does get it? Makes life hard.

Plan at this point is to take a small steel brush and go through that door and scrap off all the old junk/gunk/rust. Get it down to where it's got some metal to work with. Then hit it with rust converter, and I'm going to see about using that flex-seal stuff. If the leak comes back? I'll drill a few drain holes in the floor of the cab area where the water likes to sit, and use a rubber grommet to keep rust at bay.

Just need to get the rust brushed off, and then something to seal the gap/hole. I'm tempted to see if I can purchase the thick rubber sealant the factory uses on the seams. But at least it's an area that I can get to (somewhat......) Dash goes back in tomorrow. Need to customize the radio hole a great deal using parts from my old dash.

And for the kids reading this considering a universal car radio? Please don't hack up your dash hole to the point there's nothing left.....It's going to take me cutting out that section of my old dash and epoxy/glueing it into the new dash. I hate poor install jobs....

S-

Mark_88 said:

You might be able to make that doggy door a bit bigger but it would be close to losing a bit of the integrity of that area...I'd be interested in seeing that if you have time to document it...although I know what that is like with my own repairs...I get going on it and by the time I realize I should have taken some pics it's too late...

I used some aluminum tape on one section that was almost impossible to fix otherwise. it is super strong and I coated the area with rust converter then painted it with rust paint...once it dried I put the aluminum tape over it and hope it lasts...lol

That's usually the end of the cab if you aren't able to fix it...for someone else to do it would cost a small fortune, but it would save the cab for decades...

Click to expand...

Where abouts did you purchase that tape? It might actually be a decent idea. Clean it up and hit it with the rust converter--and then a good layer of the sealer spray.

S-

I bought it at Rona (building supply store) and it was used to seal ducts or apply that aluminum wrap on pipes...it's called just aluminum tape and I can't remember the brand name...even though it's probably printed on the inside of the roll...

It is very strong and I had used it several years ago on something else...and was surprised to see it was still there...oh, right, I sealed a hole in my door from those wide side mirrors for towing...then I covered it with body filler...only discovered it when I took the old doors off and was looking at them and remembered how I did it...pretty amazing seal and tough too...I will look for the brand name...might be sold in the US under a different name though.

home depot or lowes should have it. don't remember where i got mine but just used some to finish patching wifes floorboard. you could use a roof cement the kind you put on with a trowel it is fiber reinforced and it will seal even if area is wet when applied.. http://www.lowes.com/ProductDisplay?partNumber=12011-29-6230-9-34&langId=-1&storeId=10151&productId=3009894&catalogId=10051&cmRelshp=req&rel=nofollow&cId=PDIO1

Dow 5200 (ACE hardware, etc.) is a great sealer for this type of stuff. It was developed for aerospace sealing; but, is used extensively in the marine industry for sealing below the waterline hull fittings.

It is really sticky and messy. Put it on a clean surface and it will be there forever. It has some flow capability so it will get down into the seam. Wear gloves or you will have it on your hands until it wears off. When wet it can be removed with thinner. Once dry, nothing that I know of will remove it.

Wound up using rubberized sealer. Kinda like undercoating seal by rustolium (never could spell it) Did the silver tape after wire brushing off all the gunky rust, covered it and gave it a couple of coats. If that still leaks, the fender comes off again and I'll use the heavy duty stuff and go to town with it.

We might have a leak in the same place on the drivers side. Minor at this point, but the carpet was pretty wet on that side when we had things apart.

Can't win for loosing. At least the dash is in, the harness is patched up from the really bad radio install someone did years ago. (Buy a flippen ADAPTER PLUG!! Don't hack up the wiring!!!)

S-