In October I bought my first Jeep. A 2001 XJ with the intent of making it an off-road family hauler that we can pull behind our motor-home. Since I live in the Chicago area. . .and I wanted to keep this project reasonably cheep. . .I settled on a XJ that was in great shape mechanically, had a great service history, and had no major rust on the body, but plenty of rust in other areas. The idea being that, as long as it wasn't structurally crap. . .I could talk the owner down to a reasonable purchase price. Here in Chicago. . .XJ's don't really sell for less than 3K even with rust rust holes in the body or rockers. Ultimately I had to replace the driver floor pan, and grind down rust in the door sills and undercarriage. Rather than taking everything down to bare metal however, I decided to leave the surface rust in place and hit everything with POR-15. Yes, POR-15 is expensive. . .but it works better than anything else I have tired. I should have taken before and after photos. The last step I will take is to coat the frame rails and the rockers with Eastwood internal frame coating. I will also RTV seal the plastic sill plates and the sill vents in the back door jambs to help prevent water from getting into the rocker area. I don't know why Jeep decided to put the door weather strips on the body, and not the door. The amount of water that runs down the jambs an into the rockers from under the plastic sill plates and that plastic vent thing is shocking. It's no wonder why the rockers rot out quickly on these things.

 

You just described 2/3rds of my "Rust Retardation Program". LOL. Can't comment on the Eastwood Internal Frame Coating cause I can't see in my uni-body. But used it anyway. POR 15 has been applied to quite a few areas of my Jeep. Every time I open up an area, like when I replaced the whole exhaust from the dual front cat back, I cleaned it up and went to town with the POR 15. Love that stuff. What I also love that you should check into is Fluid Film. Google it to see what I am talking about.

 

I take my Jeeps in to Krown Rustproofing once a year. I also apply Krown T-40 to parts of the Jeeps as I work on them. I use a basic syphon feed pneumatic gun with a fluid pot. It's pretty good at getting internal areas of the unibody and it's perfect for easily accessible/visual areas. T-40 also comes in aerosol cans.

As for specific areas of an XJ, here's one that's often over looked. I posted this a few weeks ago so sorry for the repeat. The photo's are self explanatory. Other than spraying T-40 into the body the only additional things I did was use a different kind of drain plug (from a hardware store) and drill three 3/16" drain holes above the bottom seam where none existed when they were made. Water will now drain out the bottom. This is a common rust trap as this area can fill up with water from imperfectly sealed rear side windows.

I'll be applying POR-15 to the small surface rusted area in the 3rd photo ... as soon as the snow melts!

 

It's not clear where you installed the 3 new drain holes.
I don't see it in the photos.

 

The picture with the tire in view. From left to right what you are seeing is the rear bumper end cap, rear quarter body panel, then the fender and tire.

The holes are created at the lowest point on the inside of that body panel underneath the vehicle. Typically as close to the rear tire as possible, because it is lower. There is a picture showing the plug installed.

This lower rear quarter panel area sits right behind the rear wheel wells, and can be visually inspected on the inside when your pull your tail light boxes off the body. These lower areas have a reputation for holding over a gallon of water in them for months at a time, if they can't drain. Water can find its way into them from leaking rear windows, hatch problems, CB antenna holes, etc. These areas are sometimes called the "Fish Bowls" on an XJ.

 

I think I get it.
When do you pull the stopper and drain it?
I don't understand the point of the stopper in the first place.
Why not just drill a hole and leave it open?
Do you climb under the car and unscrew the wingnut every time it rains?

 

Do the earlier XJs not have the rear-facing weephole in that location? I just get under there and clean mine out on occasion to keep it from stopping up.

 

Mine are huge gaping holes due to rust, ha ha. I'll try to get it fixed next year. I spray some T-9 aerosol into the frame rails and all over the under body once a year. Keep it clean in the winter, and hope for the best.

 

Unfortunately the holes don't show in my photo. It's at a bad angle and they and they are small (3/16"). Jordan's explanation below is very good.

"Fish Bowls" is right! I haven't removed the tail lights from this XJ yet but will. It's a good time to clean the inner body panels up, apply some POR15 if necessary and spray some rustproofing.

I replaced the plugs with the stoppers. I was actually missing one plug. I think they were initially meant for allowing rustproofing to be sprayed in vs. water to be drained out. I will only take them out to spray rustproofing in. Leaving it open wouldn't be all that bad. It's a 1" hole. Some road crap would get in but it's no different than the holes in the sub frame (thinner metal though).

Good question. Mine is a '89 and it fully enclosed ... or at least I didn't see a weep hole.

My '95 XJ had that feature too ... "huge gaping holes". It's a common problem and often "fixed" by removing the metal entirely ... not mine but like this ...

 

This is the drain/weep hole on the late-model bodies behind the black plug. This is sort of a stamped dimple that has a opening at the back, so that spray from the tire doesn't go directly in. It probably wouldn't be too hard to duplicate the orientation on the earlier bodies.

 

Tbone289 - Are you referring to what looks like a small vertical slit to the right of the rubber plug? If so, my '89 does not have that. That's very close to where I drilled a small hole for drainage. I put in 3 holes per side, each about 3" apart.

 

Yes.

 

There is no magic cure for rust, once it has started the only way to stop it is to cut it out, replace, properly prime the repaired area inside and out. And that is an impossibility 99.9999% of the time.


You can "stop" the advancement of rust if you 100% percent remove the moisture and air,, another impossibility.


Pulling the carpet out, wire brushing and painting with (fill in the blank with any one of the "Miracle" rust converters), only makes "you" feel better, it does not stop the rust.


Spraying in a moisture displacement product every 6-12 months does help, it blocks the air/moisture.


We are currently replacing rusted out rockers on a XJ,, cutting out all the bad metal. Sandblasting all surrounding metal and treating with phosphoric acid, coating all with Zinc/Chromate Alkyd primer, then a top coat. When we install the new metal, we will be using Fusor "weld thru" panel adhesive and a Spot welder. The panel adhesive permanently seals the seam. We will then use a wand to coat the interior areas with a body cavity wax.


The problem with products like POR15 is , the rust is still there, the miracle coating WILL develop crack and now TRAP moisture under this coating, accelerating the rust out.


Remember, rust never sleeps,, but we just want it to take a short Nap