That is a common trait of the fifth gens that many don't know about. I know of no patch panels. In my case I cleaned the area very well & applied a fiber glass patch from a kit to the affected areas. It worked very well & is still holding up. Jon
That's a good idea! I'm still going to have to use some metal on a couple of places because of the size of the holes. I was thinking on metal patches and then using the 3M rubberized undercoating over that. I've used it before with great results on other areas.
Well, this morning I headed to the shop to tackle the floor pan problem and ended up making a patch panel for the area right behind the front seat then used some of that fiberglass bondo that 7D8SS talked about. I was using an impact hammer to knock the loose scale off but had to quit because I was causing more damage by punching holes through the already thin metal due to rust. The problem with these 5th gen cars is the body brace that runs diagonally under the smugglers box. The brace houses the nut that the side body mount bushings bolt to and it has two holes in the bottom of it. The road crud goes up in through the holes and just sits there and rots the metal (the same guy must have also designed the rear frame horns, too). If you guys have a 5th gen, you might think about drilling some holes near the ends of each brace and then get in the larger hole that is already in there and hosing the crap out of those things. I blew out all the rust scale and dirt out with an air compressor then took some of that GreatStuff expandable foam and filled the void in to keep the water and dirt out. I have finally come to the conclusion that I'm fighting a loosing battle in keeping the rust from forming but will give it my best attempt in slowing it down. The best thing I've done is stop driving it in the winter!!! I'll post some pics of my progress later this week.
Wayland46, it's the storage area behind the seats where the spare tire is, or is supposed to be. El Camino owners call it a smugglers box because most people don't know it's back there. Hence, a perfect place to "smuggle" things.
I had the exact same situation, but my box was killed allmost up to the back seats. i bought two pieces of sheet metal, 2 or three cans of Great Stuff (AWESOME) and 4 cans of rubberized undercoating. plus a billion rivets. the rubberized undercoat ontop of the greatstuff is telling salt, water, and road dirt from my tires where it can shove it.
so either way what im saying is it sounds like youll be fine it has worked for me. :-D
-oh and while your in there you should also fill up the space between the back of the box and the lower qt panel w/ greatstuff ect ect.