Help: 84 GMC 3500 Help me find water leak source

[2badgn]

The truck was painted and under the hood rain tray was cleaned well. The windshield and gaskets were changed.

Before the paint, it still had the same leak.

Its a tiny drip on the driver's side right by the emergency brake pedal.

Truck only has heat. Could it be the vent door?

Please help

Thanks

[tucsonjwt]

My 76 had the same problem, but on the passenger side. The opening for the windshield gasket is like crimped metal. Up in the right corner the metal was not crimped flat - a small sharp ridge of metal stuck up. The windshield gasket covered it, but there was enough of a gap to allow water to pass through and drip onto the passenger side vent area. It was this way from the factory, so the water collected under the carpet and eventually rusted out the joint between the vent area and the floor. I had to get that whole area repaired (rust on an AZ truck). Safelite installed the windshield, so I took it back to them twice and they put gobs of silicone around the bad area but it did not work. Finally a convinced them to tap that raised area down with a hammer before the gobbed it up again. I sold the truck shortly thereafter so I just assume that the fix worked. I see streaks on both kick panels on my 83, so I don't know if this is another windshield problem or just condensation drips - I have A/C. Unfortunately, you can't tell if you have this problem unless the windshield and gasket are out of the truck. Good Luck.

[donut]

Any little pinholes in the cowl area (up against the firewall)? Cab lights?
I had a seal on a cab light that was leaking and it ran down the windshield/door post and collected by the vent area.

When the windshield was changed, did you get to inspect the windshield channel itself? Mine had 1/2" wide by 10" long holes rotted into it instead of the little "weep" holes

[old Rusty C10]

i think you have a typo the parking brake is on the left side of the truck or is the leak to the right side of the parking brake?
have you checked the underneath with someone running a hose up top Usually its something in the cowl area with a hole or the windshield gasket

[dropd80s]

Originally Posted by old Rusty C10

i think you have a typo the parking brake is on the left side of the truck or is the leak to the right side of the parking brake?

He said its right by the parking brake, as in close to it, not on the right side.
All of the places mentioned are good places to look.

[RandyP]

Water leaks can make you go crazy, that's the only certainty. Best way we chase them is, have a person get inside where the leak is, with a flash light, have another person start with the water hose. Start low, and work the way up with the hose stream.
It's not so bad in a cab, usually end up laying in the floor board or being upside down. Inside a trunk though, sucks for the little guy in the shop, which ain't me! I chased a water leak on the firewall in an el camino once, I ended up using sprayable seam sealer and just coated the dang firewall inside and out, that fixed it!