XJ Forks - Pitting and Leaking Seals

[Prothec]

I finally pulled apart my XJ forks to address my leaking seals, with new seals and brake pads coming this week. What I have realized is the amount of pitting in the upper tubes, which must contribute to leaks and accelerated wear on the seals. Over full travel of the forks, the seals were dragging across this sandpaper surface.

Has anyone bothered to try to fill in the pitting? Or is it best just to clean them up, check for sharp or rough surfaces and move on?

I was reading on other sites where people have recommended using super glue or epoxies with the obligatory warning against using materials that could come loose in hydraulic systems. There was talk about aerosol metal filler products as well. I'm not concerned so much with visual appeal, while the emphasis is with function and longevity.

Here are a couple of shots of what I have going on with one of the forks:



You can see the lower is still covered in oil and grime. I'm planning to meet up with some friends to put some miles on her next Sunday as long as I get my parts this week.

[skids]

Wow that is bad. Getting anything to stick to chrome would be tough, especially with oil impurities. Forks by Frank?

[skids]

Looks like the sand you have been riding through has diamond bits in it!!

[crazy steve]

Yeah, those are pretty bad.....

One thing I've had pretty good luck with on rusty parts is buffing them with some Tripoli compound on a buffing wheel, just like you would for polishing aluminum. The chrome is 'hard' enough that the compound won't take it off. That will remove all the surface rust and help smooth any sharp edges. Keep in mind that the rust will come back quick if you don't keep the part clean and well-waxed. It will probably come back eventually in any case, but this will at least get you by for a while. Stay away from sandpaper, steel wool, etc as all those will leave a rougher surface and prematurely wear new seals.

But you might try some of the new rust removers, like Metal Recue to get all the rust out. You could then try some silver paint to seal the bare metal, then use some chrome polish to remove the 'excess' paint.

But at some point, new fork tubes are in your future....

[Prothec]

Skids,

I've seen the forks by Frank links on the forum, but haven't seen anyone report back... Know anyone who has gone that route? I'll probably search some more and pick the most likely quick fix, polish and reassemble to deal with it so I can ride, then keep an eye out for a good used set.

[Prothec]

Yeah, those are pretty bad.....

One thing I've had pretty good luck with on rusty parts is buffing them with some Tripoli compound on a buffing wheel, just like you would for polishing aluminum. The chrome is 'hard' enough that the compound won't take it off. That will remove all the surface rust and help smooth any sharp edges. Keep in mind that the rust will come back quick if you don't keep the part clean and well-waxed. It will probably come back eventually in any case, but this will at least get you by for a while. Stay away from sandpaper, steel wool, etc as all those will leave a rougher surface and prematurely wear new seals.

But you might try some of the new rust removers, like Metal Recue to get all the rust out. You could then try some silver paint to seal the bare metal, then use some chrome polish to remove the 'excess' paint.

But at some point, new fork tubes are in your future....

Good idea, I didn't think about using a metal prep like that. I would think any sort of paint would get stripped pretty quick regularly coated in fork oil.

It will be interesting to see what the inner lip of the seal looks like when I pull it. As the air preassure dropped and the forks could ride up higher and higher into the really bad surface, I imagine it left its mark.

[WMarshy]

Keep in mind that if all you do is knock off the rough corrosion and chrome you are left with a spot in the tube that has a small pit. That small pit will transfer oil under the seal every time it crosses it and slowly bleeds down your fork oil even with new seals. How much depends on how many and how big the pits are. Filling in the pits is key and I'm not aware of any material or process to restore its condition. As previously mentioned, forks are in your future... time for FJ fork mod?

[DGXSER]

I am sure you can get new fork tubes, and as the others have suggested, that is really your best bet. Fortunately, none of mine have been that ate up and certainly not in the portion where they travel.

[Bonz]

Bonz says... Ditto on new forks/ tubes.

[CaptonZap]

CZ says, try C Steves method, and let us know how it works out. If you worry about oil getting on the rubber seals on the brake calipers, you can get some kotex and zip tie them around the slider seals. Change them when necessary.

CZ

[TopCatGr58]

Hey there,

I've used forks by Frank a couple of times. First when I had a bad front ender collision that bent mine into my engine! And I got them made 4" over length!

Then, some 20 years later after mine had sat for ~10 years outside with a dead tranny, ordered another set, also same length, and have worked just fine! That was in 2000 and they still look and work great...albeit the bike is now garage kept!

T.C.

[Prothec]

I will replace the tubes at some point, but for now, I'll try a temporary fix. I don't really have much to lose.

Here's a picture of the bike when I was picking it up from where it sat for around 25 years...

[jetmechmarty]

I have heard of folks using JB Weld to fill the pits. I used it to restore a wheel that was pitted in the bead area. That worked very well, but it is a big chore to smooth that stuff. If time is money, then Forking by Frank is the better deal by far.

[Prothec]

Well, I tried cleaning up with aluminum foil and heavy doses of brake cleaner, then JB Weld (the kwik weld or whatever it is), then set up a day. Now that I'm done sanding and polishing, I'd say I should have just skipped the JB Weld. I think it pretty much just pulled out of the pits (more likely didn't go in) while sanding. It'll have to do for now. I'm planning to be spending quite a bit on my 78 that I'd like to get running before the end of summer.

Now to wait for pads, seals and a hand air pump to arrive...

[Prothec]

Oh, and I did finish then up with the buffing wheel. Slow going and cumbersome with my bench grinder, though