When i found out my Ranger was taking on water i had to track it down to stop it. I ended up taking my whole dash out because where you windshield wipers are the drain tray (what ever it is called) had leaves and pine straw sitting in it. I found tons of rust and a few holes. It was leaking so bad from the fire wall that I had an inch of standing water on the floor board. Puts a whole new meaning to car pooling.
I cleaned everything, on the fire wall, up put Rustoleum Rust Reformer on it, for added protection, I patch all that with JB Weld stick (two part epoxy stick). If you do a light sand before the JB weld it will stick better. Then after that I used seem sealer around the edges of the JB weld and let that dry and painted it. Then i used Dynamat on the fire wall to cover everything, also to dampen the sound of the engine. Then in the Drain tray, were the wipers are, I bought a self leveling caulk and squirted it in there and let it dry and have not Had a leak since.
I said all that to say this; on the floor I painted it with that rubberized spray for your under carriage. I pulled up the factory insulation and then painted it. I would buy some Dynamat for road noise it is awesome stuff I lined my doors with it and it cut down on the road noise tremendously. I used MIP (molded industrial polly-vinyl) on my floor board. I bought it from
http://www.lmctruck.com it is a little pricey but worthy it. It is tough stuff. hope this helps.
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