There is a substantial water leak behind the dashboard of my 1990 Toyota pickup. The firewall under the windshield has rusted away and is leaking down behind the fuse box and into the drivers side of the cab. I had to replace the windshield and noticed the holes in the body. Whenever it rains, it leaks.

I need to stop this leaking and wonder if anyone else had this problem and what they did to fix it. I hate working behind the dashboard, it looks like removing the entire dashboard would be the best way to get at the problem area.

Any ideas or insight?

 

Just how much of a project do you want??

Maybe the better question is how picky are you??

Take us some pictures .

I had a leak on the other side down onto the ecu after the third one quit I broke out the caulking gun one tube of silicone later no more leak .

Going on two years and we have been getting great rain storms.

My other option was pull it all apart remove the wind shield weld in new pieces.

1 tube of silicone 20 minutes plus cure time compared to a few days most likely a new windshield .

It worked for me.

 

Being able to get to the spot that's leaking is the major issue. The water is coming in just below the windshield so it's hard to see anything or get a tube of silicone or even your hand up there.

 

Leaks like this need to be sealed from outside the cab. If you try sealing it from the inside it'll work for a while but water will still come in through the hole and collect between the sealer and metal accelerating rust.

You may have to pull the cowl off under the wipers and possibly the fenders to get to it.

Mine was leaking bad and it turned out to be a seam rusted out causing the sealer to let go. I found that polyurathane used for windshields worked great to seal it up

 

very common issue on lots of brands of cars - lots of metal seams in that area and also lots of debris tends to collect there and rust when it holds moisture up against the cab steel. your only real fix is to take it apart and weld in solid steel, very very time consuming. the other fix is like described - goober up the silicone/epoxy/whatever to seal it up and cross your fingers. yes, there's a high chance the rust will still continue after the repair.

i'm dealing with a similar issue on my Oldsmobile - debris collected up under the windshield/cowl area and then plugged up the drain at the bottom of the A-pillar...now I have rotted out lower door hinge pillars on both sides. My car is a 2yr only body style with zero aftermarket parts. At least on the Toyota they were made for longer time and parts available on any continent.

 

When I had to replace my windshield, I noticed there were a couple spots that needed to be repaired. I'm trying to figure out if I can take off that vented cowl under the wipers without ruining the windshield seal. Or would I have to take the windshield out?

 

Sorry I should have mentioned all the caulk went on the outside.

That was the basis for my " How picky are You" comment

It is not pretty but it is still dry.

 

You don't need to pull the windshield to remove the vented cowl. The cowl is held on with screws near the weather striping at the rear of the hood. Pull the windshield wipers, remove the screws (I "think" there's 4) and the cowl should lift off.

 

I know what you mean. I want to be sure I can take that part off without wrecking the windshield gasket, swap one leak for another...