North American Turbocoupe Organization

Full Version: Potential Rust Areas
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Hey all, I noticed my 87 TC has seam sealant inside the rear fender wells that's busted. I'm not talking about where the outer skin meets the lip, I'm referring to the center section of the fender well/Center tire tread area.
I recently had issues with my Bronco II where that seam sealant cracked and let water in but couldn't dry out. Therefore, a major rust area ate through my outer sheet metal skin.

At this point I'm thinking of using some Rubber Undercoating to seal it. On the other hand, I've never liked that stuff because it's too tacky & messy. Anyone has suggestions on how to fix this area ?

Next, the front fender wells (plastic) tend to hold road debris. I unscrewed the bottom screws just in front of the doors and all kinds of $#!T came out. Please take my advice and clean this area if you haven't already. I used a water pressure to clean it out further. Then I left the screws out/loose at the bottom so I can clean it more frequently.
Thanks for the tip. I'll be checking mine this weekend.
It's pretty straight forward. Chip or Grind the rest of the old seam sealer out, don't just paint over it or apply new seam sealer over the old, (or you will be sorry later on), lay down a rust-preventive coating (like por15) over the entire area, and then apply the new seam sealer. 3M being the top of the line choice, Eastwood also makes a good mid-range seam sealer. With today's seam sealers, if you do it right, you won't have to worry about it again in your lifetime.
Actually, while we are on the topic I also recommend checking the Hood Latch Cable going through the fire wall/kick panel. All three of my TCs have leaked there.
Next, there is some Insulation (bags and mat) behind the door hinges that hold water. I just took mine out all together. Nice and dry now days.
Third, window trim should be removed and repainted or rust encapsulated. When I had my windshield replaced it showed rust at the seams.
Forth, if you ever have to take off your door interior panels for anything you should clean and reseal the sheet metal/drain area. Mine are currently off due to bad window regulators. I noticed after it rained the Dew Wipes aren't really water tight.

Anyone else have a suggestion ?
A few common places to check, from what I've learned on these cars over the years:

Front Fender, top inside lip of the wheel arch. Dirt/debris accumulates there, holds water, and rust's out the fender arch from the inside. Need to spray it out with high pressure water at least once a year.

Front Fender, bottom rear, where the fender bolts onto the body of the car. Can hold alot of debris, and in turn moisture, rotting out the thin mounting point of the fender itself. Take one bolt, and a few screws out, and this area is easily cleaned out.

Bottom Seam of both Doors. Water naturally beads and sits here. Crappy factory seam-sealer always hairline cracks there, allows water to enter the seam, and sit there for days on end, eventually starting some killer rust areas underneath the old sealer. If not fixed, eventually the outer skin of the door at the bottom where it is folded over the inner structure, will rust out, and separate from the inner support structure. All 80's Ford's I have seen have this problem. Grind out all the old seam sealer, apply Por15, and replace with new sealer.

Inside of both Doors. The water drain holes inside the bottoms of both doors will sometimes get clogged up with debris. Causing water to sit inside and slow drain. Over time this will cause rust. Remove the door panel, pick out the large pieces of debris by hand which are to large to go through the drain hole, and use a garden hose to spray out the inside to get it fully clean. Make sure that the drain holes are easily draining water afterward.

Rear Quarter, exterior, underneath the bumper beltline body trim. Holds dirt/mud behind the trim piece, which in turn holds water for days afterward everytime you drive in the rain, and slowly rusts out the rear quarter section underneath the trim. Common spot to find rust on these cars. Remove and clean.

Rear Quarter, spare tire area inside trunk interior. If you have a leaky trunk water can pool here on either side, and rust out the seams. If you can't stop the leak point completely, you will have to drill drain holes in the bottom inside of the RQ near the seam, to let the water drain back out each time, or it will never end.

Trunklid, bottom outer lip seam. Water beads and sits here naturally as well, once the seam sealer cracks, it doesn't take long for rust to set in. Most probably know if they have rust here or not, since it's easily seen once you open the trunklid.

Engine Bay, Underneath the Battery Tray. Holds a lot of debris, when combined with an old leaky battery over time, it can be horribly rusted out underneath here. Doesn't take long to check.

Interior, DS & PS front floorpan outer edge, underneath the carpet/insulation. This is the main place where water accumulates once it comes in through your windows or firewall seals.



Basically anywhere there is a seam, or a place which can hold dirt/moisture/salt for long periods of time has the potential to be a rust area given enough time. Never just assume you have found them all without going over the entire car with a fine tooth comb. There are many more, but those are the most common places for people to check on our cars.
My symbols were loose when I bought my car (Rear Quarter Birds and Turbo Coupe on the trunk) so I plugged those mounting holes with JB Weld. The trunk rust you mentioned could be caused by a loose symbol. If I do remount those symbols I'll just use two sided tape and leave the holes plugged.
goldwing Wrote:The trunk rust you mentioned could be caused by a loose symbol.


Smile Not quite. The trunk rust that I was speaking of being common on these cars is found a little below the symbols. Like on the very bottom inside lip, where the 2 halves of the trucklid (inner/outer) join together. It's called a seam. Rust is common place at seams that see alot of moisture exposure. Here because of the sloppy seam sealing job Ford did on most of these cars.
Thanks to your advice I found my spare tire department holding about 1 inch of water. Man, that darn loose side molding bolt cause all sorts of problems. I believe steam in the hot trunk caused that seam I originally posted in the wheel well to break loose plus the seam going down from the tail light was leaking slightly. Its not 100% gone but its rusty as heck. If I didn't find it today I would have BIG PROBLEMS.

I took ALL the carpet out and found the noise/vibration mat to have rust beneath it too. I've began scraping all that stuff out.
I'm leaving my carpet out for good now ! This way I can keep a eye on that area plus it will help keep it dry.

Thanks a lot man !
Cool, glad I could help. Smile Those trunk seams are the worst, they always seem to leak around the tail lights. A good tip for finding all the leak points in the trunk: First get an assistant to help you out, then climb inside the trunk with a flashlight, have your assistant close you up inside, and then start spraying the entire trunk area down with a garden hose for at least a couple of minutes straight, trying to mimic driving rain force. Use a marker to circle all the leak points that you see, for repair after they all dry back out, many will be coming from seams. Sometimes the bottom of the rear window frame is rusted out beneath the window, and will slow leak in from above as well, my Lincoln MKVII had that problem.