Fork seal leaking

[sovrin]

Ok, this is my first post ever.  Need some advice.  I recently purchased 86FJ and one fork leaks oil, which goes down to contaminate the brakes.  I'm not leaning toward rebuilding all the insides of the forks(budget), I just want to put in new seals.  Do I have to take everything apart to do this?  Do the forks have to come all the way off the bike for this?  I have never worked on forks before.  I just got a Clymers manual and feel a little intimidated about the whole fork thing.

[FJmonkey]

I just rebuilt a set of forks myself last week. To put 1 new seal in I would recommend removing both forks and swapping both seals. Before doing that, get a really thin but stiff piece of plastic. Much like the new bubble packing that can cause injury trying to tear open. Push it up against the upper fork tube so it curves with the tube and slide it down into the seal. Slowly slide it all the way around the seal and test again for leaks by compressing the forks or a short ride with bumps. Some leaks are caused by crap getting stuck in the seal. Once removed the leak clears up. On the other hand, if you don't know how old the oil is or how long it was leaking (loss of oil) then new oil and seals are in order. If oil has leaked on your brakes then you also need to deal with that contamination for safety reasons. Take the calipers off and clean them up getting all the oil off. Thake the pads out and blast them off with brake cleaner. If your pads have been used with oil on them then you may have caused some glazing that will need to be sanded off. Check your rotors, When my fork seal leaked on my 86' CBR it made the pads really abrasive and cut deeply into the rotors. You will need some special tools that you can make yourself. A few hex shape tools and a seal driver, easy to make from PVC pipe bits. Search the sites in the files and maintenance sections for this info. Maybe you are near fellow members that work for beer like me. Good luck.

Welcome to the club and the Kookaloo zone, we will help you get your Kookaloo on.

[soundmindryan]

Ok, this is my first post ever.  Need some advice.  I recently purchased 86FJ and one fork leaks oil, which goes down to contaminate the brakes.  I'm not leaning toward rebuilding all the insides of the forks(budget), I just want to put in new seals.  Do I have to take everything apart to do this?  Do the forks have to come all the way off the bike for this?  I have never worked on forks before.  I just got a Clymers manual and feel a little intimidated about the whole fork thing.

Easy peasy, lemon squeezy. Just like FJ Monkey says, there are a couple of files in the 'Files' section that make it so. The only thing that is really helpful besides what's listed in the files is a good bench top vice, for holding the lowers while you slide-hammer the tubes/seals/bushings out. Especially check out the files regarding fork seal installation tools and fork information in the "Suspension Related Files" S'all there.
Ryan

[rktmanfj]

http://www.fjowners.com/index.php?topic=6299.0

[FJmonkey]

The only thing that is really helpful besides what's listed in the files is a good bench top vice, for holding the lowers while you slide-hammer the tubes/seals/bushings out.
Ryan

I used one of them multi-purpose sawhorse like things that can clamp things in the middle like the fork lowers, like this http://www.harborfreight.com/folding-clamping-workbench-with-movable-pegs-47844.html. But you don't need it to slide-hammer/knock out the old seals. I just held each end, slid them to full open a few times and the seals pulled out and sliders became two pieces.

[soundmindryan]

But you don't need it to slide-hammer/knock out the old seals. I just held each end, slid them to full open a few times and the seals pulled out and sliders became two pieces.

You BEAST.

[sovrin]

Thanks Ryan and FJMonkey.  I had already tried to clean for potential dirt caught in the seal.  A friend told me about something easier than the plastic you referred to.  Photo negative from 35 mm camera.  I dug out some old photos envelopes and found a strip of 35mm negative and slid it right down there.  Great idea, just didn't fix it.  You all be good.

[FJmonkey]

You BEAST.

Beginners luck actually. If I read that I needed to clamp it I would have. I was not sure how to pull them apart and kept sliding them to full open a little harder each time. I saw the seals working out and kept going. About 5 or 6 hits was all it took, not hard hits either.

[SlowOldGuy]

Slide hammer the forks while they are still in the triples.  If you've already removed tham, then just re-clamp them.  A "WELL-supported" bike provides a lot of inertia for separating the sliders and tubes.

Seals and oil are cheap!  Replace both as a minimum.  You probably don't really "need" to replace any of the other fork components unless there is damage.

The ONLY way to repair fork oil contamination of caliper seals is to replace the seals, the oil causes them to swell and degrade, very bad situation.  Your brakes will never work correctly with bad seals and will probably leak brake fluid that will blow back on to the paint and ruin it, cheaper to replace the seals.  Unfortunately you can not upgrade to monoblocks, you can buy them (with pads) cheaper on eBay than what the stock caliper seals will cost.

The ONLY way to repair fork oil contamination of brake pads is to throw them away and get new pads.  Believe me, I've tried everything.  Cheaper to get a new set of pads. 

DavidR.

[fj11.5]

had nothing like a vice or work bench at the time i did my fork seals/ conversion , just used what i had a length of 12 mm threaded rod in the axle hole and body weight , stood on the rod and about the same as monkey did just worked them out till they were 2 , probably looked odd if anybody had been watching but worked well enough  

[markmartin]

 I agree with David about leaving the forks in the triple clamps.  He suggested this to me when I did mine and it works perfectly.  No muss , no fuss.

Sovrin, if you want to get a look at the innards of the fork assembly, check out the attachment at the bottom of this post. (found in the 'files' section.)

http://www.fjowners.com/index.php?topic=1911.0
You wouldn't be cutting your damper rod adjuster, drilling holes in your damper rod, or adding emulators, but it does go through the process of replacing seals and gives you a good look at the what's all in there and what's involved.

[FJmonkey]

had nothing like a vice or work bench at the time i did my fork seals/ conversion , just used what i had a length of 12 mm threaded rod in the axle hole and body weight , stood on the rod and about the same as monkey did just worked them out till they were 2 , probably looked odd if anybody had been watching but worked well enough  

ya don't use brute force to pull them apart!!! use the inertia generated by sliding them apart. The faster you slide them the harder the hit and the more distance the seal gets knocked out. You could do it with one really good-fast slide apart. That is why a hammer works so well on nails. We don't use a hydraulic ram to push nails in, you hit with a hammer blow. Or am really that much of a brute? More pot bellied and lazy I think.

[sovrin]

Thanks to everyone for the tips.  I'm going to dive in and see what happens.  If I get stumped, I'll just come back here for more advice.
I'll let you know how it all works out.  This old FJ didn't get treated too well by previous owner.  53K miles and kinda rough.  Still runs strong
though.  One thing at a time.

[sovrin]

Ok, I'm at the point I'm trying to get that stubborn cap out of the top.  Mine is an 86, so it is the 27mm size.  Clymers tells me to take the rear axle nut (27) and put it in there and then use a wrench on it.  Supposed to raise the dampening adjuster to highest setting so the axle nut "splits" the height and you can get a wrench on it.  My problem is that the axle nut just doesn't fit good enough and when I apply pressure, the axle nut just pops out of the top.  Any ideas??

[FJmonkey]

Ok, I'm at the point I'm trying to get that stubborn cap out of the top.  Mine is an 86, so it is the 27mm size.  Clymers tells me to take the rear axle nut (27) and put it in there and then use a wrench on it.  Supposed to raise the dampening adjuster to highest setting so the axle nut "splits" the height and you can get a wrench on it.  My problem is that the axle nut just doesn't fit good enough and when I apply pressure, the axle nut just pops out of the top.  Any ideas??

I had the same problem but with the fork out of the bike. You have to push down hard while turning. The socket is tapered and will act like it is pushing the axle out as you put more torque on it. Just push down hard. Once it breaks free it will turn much easier...

Keep some pressure on it while you are turning it out. There is still some small spring force on it. 10 pounds of force is enough to keep it from being a surprise when the treads clear the fork tube....