My '95 Caprice Classic STW, "Sally"

[Arquemann]

Possible pinhole rust? Leaks through the outer skin but catches on the inner skin and down the A pillar. That's my theory and I'm sticking to it.

Could be, but I was feeling water on the edge of the pinch weld on the top area of the windshield. Wouldn't be surprised if the pinch weld isn't completely sealed. But I did pay for the glass guys to eliminate any rust around the windshield prior to install, they wouldn't warranty the replacement otherwise. It does have some bubbly bits on the top edge, but shouldn't be so much to be rusted through.

Earlier I lifted out a part of the trim on the top of the windshield and poured water in the channel, and that's how I got water slowly appearing on the pinch weld.
Since it's the windshield area leaking, it'll be the glass guys' problem, not mine. I don't care how they fix it, fill the channel with urethane or something more professional, as long as the top trim is there to hide the sins and it won't leak, I'm fine with it.

[sly]

Sounds like a plan. Hopefully they don't give you crap about it and just get on a fix.

[Tiggie]

Am I wrong to think using copious amounts of glue and a clean surface should nearly guarantee a leak free glue in windshield? Yet I see so many of them leak. My Super Duty leaks and I understand a bunch of them do.

[sly]

It "should" seal. But if there's a little uneven section and the glass isn't pressed down far enough to make that section seal, then it will leak. Kinda why the installers I've watched work on my vehicles when replacing glass use power goop guns put a 3/4 inch (or so) bead down and when they set the glass on, lean on it a bit to "press" it on and then tape it in place just to be sure it stays put. Most leaks I've seen were from rust holes.

[gadget73]

had a leaky windshield in the Towncar when I got it. The sealer was thin in one spot. Or it was too thick in a bunch, depending how you want to look at it but however it adds up there was a gap between the glass and metal without enough goop to bridge it.

A lot of non-original windshields have too much gloop on them and yet they still don't seal for crap. Also sometimes it seems like the sealer doesn't bond with the metal on the car. Not sure if thats just bad prep work or what.

[Arquemann]

Glass guys didn't find shit, spent a day and a half looking for leaks around the windshield. They used all the tricks they had. But thank goodness it's not a mechanics shop so they don't take an hourly rate, so I don't have to pay a ton for someone to say the windshield doesn't leak.

So up next I'm probably gonna remove the passenger side roof rail, hope that doesn't go to shit and goop up the holes in the roof.
Another thing will be removing the passenger fender and it's structure. Checking all the grommets and cleaning up all the seams in the corner below the a-pillar.

I might buy a tube of butyl glue stuff, use that to goop up all the body seams and under the roof rail. But I wonder if I should just rip out the top trim off the windshield, fill that whole fucken groove with goop and stick the trim back on with a bit of modification. For some damn reason I still think it's the windshield. Though like I thought (and the glass guys said), the water I felt up by the windshield might've been condensation from the amounts of water in the floor. Bare steel and so on.

[Arquemann]

I've had the carpet pulled up and firewall mostly bare, a couple rainy nights and foggy days and I can't find a single new drop coming from the corner of the firewall, just baffles me. Maybe the water comes in from the tire spray, that goes under the inner fender which doesn't reach that low behind the tire.

One would think that a leak would be visible when there's a liter of water on the floor after a couple months with not that much driving.

[DerekTheGreat]

Get a pressure washer, have someone run it all over the car while you sit in it and observe for leaks?

[Arquemann]

Get a pressure washer, have someone run it all over the car while you sit in it and observe for leaks?

The outside of the car has been thoroughly soaked on a couple occasions with no results. Taking a pressure washer to it would probably make no difference, or if it did it'd be due to unnatural scenarios. The windshield, roof rail and cowl drains are ruled out, but there's a couple body seams and pass-throughs underneath the cowl drain and behind the wheel and that's where I'm looking next.
If tomorrow isn't terribly rainy, I'll start with removing the wheelwell and see what I can find.

[DerekTheGreat]

I pressure wash my cars whenever I wash them, I don't have water coming in. I'm not saying do it while just merely centimeters away from the car, but in a ways that might coax a leak to identify itself. Thought you said you left the car sitting for a period of time once with no water, then came back to find it with water in it?

[Arquemann]

Originally I spotted the soaked floors in november. Fixed the ac drain, dried everything and thought I was in the clear. That time I found the trail of moisture led to the ac drain, so I never checked if it was coming from somewhere else aswell. Everything just clicked into place with the ac drain, it was a no-brainer.

Since then I hadn't really noticed anything other than foggy windows, but the situation hadn't really worsened. Until earlier this month where I realized everything is completely soaked again. This time the area under ac drain was dry, but the bottom edge of the firewall insulation was wet in the passenger corner.

Since novembers drying, I've driven maybe 2000km, slightly less frequently than before november. The car sits slightly downhill at the house. One day last month I did drive in very heavy rain and through standing water multiple times, but I think I would've noticed the instant change in dampness. Also doesnt tell where the water came from, so I'm not sure it would be a one time thing.

To flood the cowl drain enough to have it go in the hvac box youd have to literally pour with a bucket straight into the cowl, or have the car very tilted towards the driver side, which it hasnt. Even then it should just drain via the ac drain hose.

Today I drove on wet streets and in the rain for about 1,5hrs, cant feel or see a drop of water under the dash anywhere.

I'll take a couple illustrative pictures tomorrow, maybe some from behind the fender liner if I get that far.

[sly]

Yeah... very odd to have found water drops up on the a pillar near the visors but now see nothing. I wonder if it was just condensation from the temperature changes.

[Arquemann]

Damn GM likes u-nuts, flat nuts and flag studs. Sucks balls, I two hours removing the inner fender, had to cut 4 of the 5 bolts on the edge of the fender and most of the flag studs spun for the stuff mounted on the inner fender.

Anyways, I got water to leak in! Spraying everything thoroughly with a garden hose, I got water seeping in through a bulkhead connector.
Kinda bummer is that the connector is in a spot where it's quite unlikely to get soaked naturally. Still a couple things going for it; it is below the cowl drain, so water could run on the underside of the cowl towards the connector. And there's the firewall insulation that's all around the connector, which does get soaked with water.

Also got a trickle in through the ac drain which wasn't leaking earlier, but I sprayed water right into the drain hose and it doesn't have a clamp (yet).
Can't find any other leaks, even the antenna coax cable grommet seems fine, although it leads into the A-pillar cavity that should have a drain in the bottom anyways.

I think I'll spray more water at things and keep looking a bit more, but this might just be it.
Next step might be to blow it all dry and get a can of cavity wax or something like that and spray it thick on everything.

There up on the firewall is the connector that leaks, kinda explains why (what's left of) the mass-backed firewall insulation was wet and from there running down into the corner of the firewall. Probably.



And here's the outside of the firewall. Top right is the same connector, cowl drain hole in top middle-ish, those ones are definitely not clogging. Antenna cable passthrough to the left of the generously applied seam sealer, will goop that too. Not much else to see honestly.

[sly]

Small victories.

[Arquemann]

Look mom, I'm a hack!
Cavity wax is too thin and runny and the underbody coating was too thick to push into all the nooks. So I used what I had on hand: all purpose indoor-outdoor construction adhesive sealer! It's elastic so it should work fine. It is also a very nice shade of b r o w n.
I used wayyy too much of it and slathered it all around the bulkhead connector, ac drain hose, interior heater & antenna cable passthroughs and surrounding body seams.
I'll wait for it to dry and check for leaks, if that still leaks, I'm just putting more on!

It's so horrible that I do not feel a shred of remorse.