JasBass

Restoring my 89 and have the interior down to the firewall. Tracking down a number of water leaks due to dried out seals, etc. All of them are settled except this one very minor drip coming from the underside of the driver side interior body panels. See pics.

I've already used 100% silicone along the windshield A pillars and that seemed to slow it but it still seeps under heavy rain. It seems to be a bit deeper than an A pillar leak. More positioned under the hood to body seal at the base of the windshield. Any insight would be incredibly appreciated. My bets are on a leaky rivet




Driver side under dash, not firewall. Bolt holes are for the aluminum cross support.



broader shot to show where the close up is

ctmccloskey

Hello there JasBass,

I have a 1988 Coupe and I had some problems after leaving my car for a couple years. I put a tarp over the car and then a car cover. I had assumed that this would protect the car while not in use. That stupid mistake on my part cost me a lot of extra money and work.

After opening the car up I had a ton of electrical issues. The worst was the fuse area. Somehow water caused corrosion on the fuse box itself. My fuses looked okay bit when I put a meter on them they had no continuity. I had to use a points file and some emory cloth to get my electrical system working properly again.

I found that the seals on the removable roof panel and the windshield were the primary problems but all my seals were going bad. Where multiple seals come together is usually where the trouble starts. My upper right passenger window is where the water was getting into the car and dripping onto the fuse block and dashboard. Your damage looks like it just happened on the other side of the car.

You should probably just remove and replace all the seals and start fresh. I did this and now everything is nice and dry inside the car even uncovered. The seals are a pain to replace correctly but if you take your time and do it right with the proper materials you will have a quieter car on the road and a dry car when it rains. The difference was amazing after I installed the new seals.

Buy the seals from a reputable company like WILCOX Corvette or even ZIP Products as they have good sales periodically. Don't forget to get the proper tools (Plastic interior scrapers) and use the original type glue (and glue remover) that GM did and the seals will last a long time. On my 1988 Coupe it cost me about $600 to replace every seal and that was just the cost of the parts.

On my car the roof panel seals were the worst, I found water in the back compartment behind the passengers seat which was getting in from either the targa rear seal or the rear window seal. When you buy the seals try to find the back window seal that has cast corners and not the glued corners on it. My rear corners are the glued type and I am seeing problems already as the corner rips apart very easily.

I believe that after replacing the seals on your car you will solve the water issue and related corrosion on the inside of the car. To maintain those seals after you replace them keep them coated with something like silicone oil or some good protective material, this makes the seals last longer and reduces squeaks in your car.

Good luck and best wishes with your car!

JasBass

Good luck and best wishes with your car![/QUOTE]


CT, I almost hate to say it after that really nice reply... I had already replaced all of the weatherstripping on the car with Latex pieces. I just purchased the car July of 17 and the seals were absolutely garbage and were the first thing I replaced. They were leaking everywhere.

New pieces: Door strip, inside and outside scrapers, windshield strip, roof panel pieces, rear bow strip, rear hatch seal. Cleaned off all the old adhesive and bad seal and used the 3m adhesive to put the new ones on. The only parts that did not come in the kit were the hood to body seals and the door to dash seals (the ones that are like $50 each). Driver side door to dash seal is mint though, passenger is rusted though and still doesn't leak.

It just looks like it might be seeping through one of the body joints at the base of windshield. Looking at the factory joining, some type of putty was used. Think it's possible that water is still traveling down the A pillar and seeping through those spaces? Might have to break out the dye for this last small annoying leak

Kevova

Have you checked cowl drain on left side?

JasBass

Completely clear and free flowing, all are. Even replaced it so that it extends past the frame.

I went out last night in the dark with a flashlight. Sometimes the way light reflects will show different than in daylight. I think I found a potential culprit. In the door well, close to where the upper door mount hinge connects, it looked like a small, prob 0.5cm piece of the body joint putty was nicked and maybe led to the inside. Hit it with some 100% silicone. Also, a couple of the joint rivets in the general area I hit with the silicone too for good measure. We have 2 days of heavy rain coming here in NC. It's going to spend some time outside to test.

JasBass

Well, after a few days of rain, not only did my efforts not fix the leak, the same exact leak popped up on the passenger side! Honestly, that's good news. Leads me to believe that there is an issue with the weatherstripping along the A pillars or at the top of the windshield

JasBass

I wanted to post the solution in case anyone else ever comes across this problem.

I removed the trim at the bottom of the windshield and found there were some places where the factory body seam sealer had cracked. Hit it with some 100% silicone. 2 more days of rain and hitting it with the hose on full blast and it's water tight

TeveTorbes

Sir, Thank you. I just bought an '89 Coupe a couple of weeks ago and i'm just starting to dig into it. I knew the targa top was dripping but after a good rain I pulled both carpets on each side and they were very wet, nearly a quarter inch water. After digging around in the cowl area, I did notice the seam sealer cracking. Your efforts have confirmed my suspicions and I won't waste time dawdling. Silicone here we go.

How did you like the latex weatherstripping? Were you able to re-use them after you found the leaks?

JasBass

First off, congrats on buying your 89! With some TLC and a little massaging, these really are great cars. Im glad someone was able to use the information. Just want to give back for all that i've learned here.

Zero complaints about the weatherstripping. I was fortunate that the leaky targa top was fixed with the new weatherstrip install, as well as keeping them nice and lubed with silicone spray lube. I was lucky that I didnt have to pull the the stripping back off when checking through the A pillars. I removed the trim on the inside and it gives you pretty good access to determine if it is leaking from there. The pillar isn't water tight and you'll see it leaking inbetween the various pinch welds.

I had a few leaks at the firewall, so definitely work through all of your water access points. Sometimes its nothing more than some of the old grommets and factory sealer that have dried out.
On the driver side: you have that stubborn one I found at the windshield trim, you have where the harness passes through the firewall, the clutch master pass through, brake master pass through, and hood release pass through.
Passenger side: ECM harness passthrough, HVAC passthrough, and the fresh air vent at the passenger footwell.
All of them I used high grade 100% silicone. Believe me, the $8-$10/tube silicone is worth the peace of mind. After going through that, I went back and painted it flat black to match surrounding trim.

If you get frustrated and need to talk it out, shoot me a message, i'd be happy to pass along my email and number.

TeveTorbes

Thank you, they are great cars. Very underrated, I'm glad I got the chance to get one. I'll keep you posted, thank you.

s4hbange1987

any links to a picture or video of how to install A pillar post moldings ive already replaced windshield

TheBlaster9001

So if I understand this right, it was leaking between the bottom of the windshield and the body? I'm almost leak-free at this point, but I have yet to look at sealing the bottom of the windshield.

JasBass

For the inside trim or the outside metal molding?

Yeah, the metal trim at the bottom of the windshield had come loose somehow. It managed to let water in and run down the driver and passenger side body wall, roughly where the aluminum dash brace bolts to the frame