Firewall Seam Leak? looking for advice

[KRob]

I am prepping to install insulation/Sound deadening. And I found this. If you look at the picture you will see there is a rusty section where water has been coming through over the years. It appears to have a seal to either side but not there. I am thinking about just filling the whole with silicone....but i am looking for suggestions.

This is looking through the Glove Box, above the heater, below the wiper motors.

The second picture, shows the hole in the center.
The Third picture has the hole to the far right and the far left is where the cab starts bending around.

[chad67]

This could be from a rust hole under the windshield glass. The raplacement cab I just got looked perfect until I took off the dash cover and windshield rubber. You may try removing your dash cover and looking in the corner right above the area you have pictured. If it is the issue, silicone will only make the water build up and leak somewhere else.

[chad67]

From relooking at the pictures you posted, I may not have seen it correctly the first time. Have you tried to spray water in specific areas (cowl, windshield, cowl vent, etc.) with an observer inside the cab to see where the water may be starting its journey into the cab?

[KRob]

Chad, Thanks for the reply. I was just looking to see how hard it would be to start installing sound deadening and saw that, so i have not dug to much further. I have not tried spraying water yet, kind of trying to stay away from any more moisture right now....see picture below. I will be replacing the window and installing new gaskets so we shall see, i guess.

I am hoping someone else will chime in with some knowledge.

Bye the way they are calling for sub zero temps tonight...urgh.

Thanks
Rob

Took this this morning....It snowed most of the day.