Interior water leak and no clue

[uptboi31]

I got a leak some where that comes from behind the dash almost right above the brake and clutch pedal and runs to the floor. I had the windshield professionally replaced and a new rubber gasket. I also had new floor pans welded in and don't want to install the rubber floor mat till I can findout where this water is coming from. Trapping water under the mat will rust out my floor pans again. It's not running out of the kick panels, just from under the dash. Anyone have a idea where it's coming from? I know if I take out the instrument cluster and glove box I could probally see where it's coming from but hoping someone can point me to the spot without doing that.

[guhfluh]

Get a hose out and recreate the leak while looking up under the dash. The wiper arm shaft seals are known to leak up there. There is also a seam from the cowl to the firewall that can leak, as mine was just doing when the factory seam sealer cracked and failed. Rust also likes to get there. There is also the brake master cylinder, speedometer cable hole and a few other places.

It's best to have a helper that can man the hose for you and start low and work your way up with the hose.

[Calfdemon]

More than likely, the gaskets behind your wiper actuators need to be replaced. After 40+ years, they are pretty much dust unless they have been replaced before, and most have not. Once those gaskets go, water in the cowl will leak down into the cab and your driver side actuator is right above your pedals. So my money is on that location.

All of the catalog stores (LMC, NPD, etc..) sell the replacement gaskets and they are inexpensive.

[uptboi31]

Ok, thanks. I will try both of your responces.

[uptboi31]

I assume the gaskets for the wiper arms are on the inside of the cab under the dash since I don't see anyway of getting into the cowl grill without taking the whole truck apart?

[guhfluh]

I assume the gaskets for the wiper arms are on the inside of the cab under the dash since I don't see anyway of getting into the cowl grill without taking the whole truck apart?

Yep. The whole wiper assembly is under the dash and removed and serviced from under there, except the wiper arms.