i have a 91 F150 std. cab. moisture has found its way into cab. any places that aren't obvious to check? all door seals good. its mostly around rear windows, yes, its a slider. any tricks to find where problem is without replacing everything?

 

rear sliders are notorious... There are also welds at the upper cab corners - might check for rust there. Might even pull the windshield trim - if it's rusty around the top there, water could get in while driving and flow to the back of the cab.

 

If thats the case, and you sound very knowledgeable, I wanna throw something at ya. I had cab marker lights, I didn't want them any more. I took em out, drilled holes in roof.(first layer only) filled gap between roof and second layer with that spray foam in a can. next, sealed up holes with silicon. it's been six to eight months, and now moisture thing is starting. What ya think? Does wonder on sound with roof foamed up.

Any tricks to keep are circulating? Window open or something? Nice truck by the way.

 

Are you getting any rust bubbles around the holes? Could be some water getting in around the silicon and running past the foam?

 

nope no rust bubbles or anything. its sealed with rhino liner and silicon. i'm just lost on this one sir.