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.
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.
Quote from: sovrin on April 12, 2012, 03:42:03 PM
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
http://www.fjowners.com/index.php?topic=6299.0 (http://www.fjowners.com/index.php?topic=6299.0)
Quote from: soundmindryan on April 12, 2012, 04:20:23 PM
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 (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.
Quote
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.
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.
Quote from: soundmindryan on April 12, 2012, 04:36:29 PM
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.
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.
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 (popcorn)
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 (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.
Quote from: fj11.5 on April 12, 2012, 05:27:11 PM
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 (popcorn)
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.
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.
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?????
Quote from: sovrin on April 13, 2012, 01:38:40 PM
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....
I had a helper pushing down real hard to keep the axle nut in place but still to no avail. I am going to have to make something. Something taller so I can depress the dampener adjuster down low, allowing me to set in farther for better grip. It is really stubborn. Probably hasn't been removed in a loooong time.
Run the adjusters down all the way in order to get as deep engagement of the bolt into the cap. I used a 3/4" bolt and ground the edges of the hex head to fit the cap. I think that you can get a more close fit of the tool by doing it this way. Patience, grasshopper. You can get it. :empathy2:
Quote from: soundmindryan on April 13, 2012, 02:21:10 PM
Run the adjusters down all the way in order to get as deep engagement of the bolt into the cap. I used a 3/4" bolt and ground the edges of the hex head to fit the cap. I think that you can get a more close fit of the tool by doing it this way. Patience, grasshopper. You can get it. :empathy2:
My tool was a 3/4 x 3" bolt with the hex ground down and tapered using a belt sander. Then ViceGrips to hold it and a PVC cap over the threaded end of the bolt so I could push down with one hand and turn with the other. Cost me about $5 USD for the parts.
Just got back from the store. Have a 3/4" bolt in hand. I will try to grind it down to a good fit. I also got two 3/4" nuts and a lock washer to go between. I'm going to try to run the two nuts tightly together on the threaded portion of the bolt, maybe I can get a wrench on that.
I can't stand the suspense! (popcorn)
Made the homemade tool, got the first cap off. Pulled out from top the long D rod and spring with washer. Thats all that comes out the top right?
Draining oil, slid dust wipe up and removed retaining clip. Am I ready to try to pull the sliders off the bottom? Or do I have to take that allen bolt out of the very bottom? remember, I am just going to do seals, not rebuild all the guts. :dance2:
Yes. Take out the fork spring from the tube and compress the forks to the bottom of the stroke. Hex bolt comes out of bottom. That frees the tubes to come out. The home-made bolt tool fits down in the tube and engages into the damping rod to hold it while you loosen the lower allen bolt. You'll have to use a socket and long extension. Read the file "Early FJ Fork and Front Wheel Upgrade" in the "Files" section. It gives you step by step instructions and parts diagrams. There's not much to it. Take your time and don't get rushed.
Be sure to REMOVE the DAMPER ROD LOCATING BOLT at the bottom rear of the fork slider so you don't destroy it when removing the damper rod bolt. If the damper rod spins, it will bend the locating bolt and that's not good.
DavidR.
"There is no spoon"
Quote from: SlowOldGuy on April 13, 2012, 04:38:53 PM
Be sure to REMOVE the DAMPER ROD LOCATING BOLT at the bottom rear of the fork slider so you don't destroy it when removing the damper rod bolt. If the damper rod spins, it will bend the locating bolt and that's not good.
DavidR.
"There is no spoon"
Yes Yes Yes. Sorry I missed THAT one. phillips head screw, bottom rear.
Thank you, SlowOldGuy!
"Then you'll see that it is not the spoon that bends...It is only yourself." :good2:
Quote from: SlowOldGuy on April 13, 2012, 04:38:53 PM
Be sure to REMOVE the DAMPER ROD LOCATING BOLT at the bottom rear of the fork slider so you don't destroy it when removing the damper rod bolt. If the damper rod spins, it will bend the locating bolt and that's not good.
DavidR.
"There is no spoon"
The other Philips screw at the bottom is a drain screw, use it. If you are removing the bolt in the bottom, now would be good time a good time drain them. This way they don't puke all over the place when you don't expect it. If the oil has been in their for some time it will be black like crude oil and really stink. Better to catch it in a bucket than wiping it up after a big spill.....
I had to stop a few hours ago and will resume tomorrow. I did remove the locator screw, thanks OLDGUY.
I have not been able to free the allen bolt from the bottom yet, I have to get a 10mm allen bit to work with impact.
Once I get that done, I'm ready to separate them. Wow, so much to do just to get to the stinkin oil seals. :wacko3:
I know the history of the anti-dive is pretty useless from what everybody says, but should I check it out somehow while
the forks are off? I wouldn't know what to check for????
By the way, you guys are all so helpful and you are making this more enjoyable. Everybody is so willing to help out, I really
appreciate it. :good2:
I assumed he was smart enough to drain the forks first
This would be a good time to disable the anti-dive by drilling 2 5/16 holes in the damper rod above the step and 90 degrees to the 2 holes that are below the step.
And it's SlowOldGuy. :-)
DavidR.
My bad SlowOldGuy, but you were pretty quick to notice!
Quote from: SlowOldGuy on April 13, 2012, 10:01:19 PM
This would be a good time to disable the anti-dive by drilling 2 5/16 holes in the damper rod above the step and 90 degrees to the 2 holes that are below the step.
DavidR.
I saw this yesterday, it saves some weight and no drilling.
http://www.ebay.com/itm/Yamaha-FJ1100-FJ1200-fork-anti-dive-block-off-plates-/251037114979?pt=Motorcycles_Parts_Accessories&hash=item3a72fa6263&vxp=mtr (http://www.ebay.com/itm/Yamaha-FJ1100-FJ1200-fork-anti-dive-block-off-plates-/251037114979?pt=Motorcycles_Parts_Accessories&hash=item3a72fa6263&vxp=mtr)
Quote from: sovrin on April 13, 2012, 10:06:57 PM
My bad SlowOldGuy, but you were pretty quick to notice!
The "Slow" doesn't apply to everything!
Monkey, if the damper rods are already out, drilling is FREE and doesn't require waiting on the postman
DavidR
Quote from: SlowOldGuy on April 13, 2012, 10:28:18 PM
Monkey, if the damper rods are already out, drilling is FREE and doesn't require waiting on the postman
DavidR
I was offering a slightly cleaner and lighter look to leaving the AD units on the forks and plugging up the holes. Offering options while the subject is current. No skin off my nose with any direction a member chooses to improve their bike. He can still drill and choose to put the plates on later down the road... Simply options.....
No drilling required...
RPM Fork Valve (http://www.rpmracingca.com/proddetail.asp?prod=M/C:RPMForkValve)
Randy - RPM
:lol:
Quote from: racerrad8 on April 13, 2012, 11:04:57 PM
No drilling required...
RPM Fork Valve (http://www.rpmracingca.com/proddetail.asp?prod=M/C:RPMForkValve)
Randy - RPM
:lol: Randy YOU ROCK! If life were as simple as you make fork improvement, the world would be a better place. Like I said, You are the first on MY list of people I'm gonna send $ to, once she's back on the road. Save a valve kit for me. :yahoo:
Quote from: soundmindryan on April 13, 2012, 11:10:58 PM
:lol: Randy YOU ROCK! If life were as simple as you make fork improvement, the world would be a better place. Like I said, You are the first on MY list of people I'm gonna send $ to, once she's back on the road. Save a valve kit for me. :yahoo:
Will do, and thank you.
I suggest since you are there with the fork disassembled you should replace the bushings as well. You will be pulling them out once you remove the fork tube, all you have to do is pop the old ones off and the new ones on.
It will ensure the new seals will seal for the proper life. I am re-doing mine because when I rebuilt them last winter I was out of rebuild kits and one started leaking after no more than 1000 miles...
If you search "fork" at www.RPMracingCa.com (http://www.rpmracingca.com) you will find all of the parts you need.
Thanks again, Randy - RPM
Not trying to be insulting, but.....
Make sure you've backed off the clamp bolts from both the bar and the top triple clamp.
Arnie
"No drilling required?"
I must have missed this somewhere, but if you leave the stock components "as is" then how does the fork valve bypass the current rebound damping and anti-dive circuits?
It doesn't seem to me that adding a valve on top of the damper rod is going to short circuit the crap going on at the bottom of the damper rod. What am I missing (other than having a couple of sets of these valves in my hands to install)? :-)
DavidR.
Quote from: SlowOldGuy on April 14, 2012, 08:46:27 AM
"No drilling required?"
I must have missed this somewhere, but if you leave the stock components "as is" then how does the fork valve bypass the current rebound damping and anti-dive circuits?
It doesn't seem to me that adding a valve on top of the damper rod is going to short circuit the crap going on at the bottom of the damper rod. What am I missing (other than having a couple of sets of these valves in my hands to install)? :-)
DavidR.
I wondered exactly that too.
Dan
me too, mine is an '86 and had planned to blank them.................
got the valves, slowly saving up for the rest
:)
I believe the RPM required 5w fork oil is too thin for the damper rod to make any effect on damping and that is all facilitated by the cartridge. :scratch_one-s_head:
Quote from: soundmindryan on April 14, 2012, 11:52:17 AM
I believe the RPM required 5w fork oil is too thin for the damper rod to make any effect on damping and that is all facilitated by the cartridge. :scratch_one-s_head:
Having just installed a set, the instructions are to preset the dampener setting to the middle setting. Then with the rod cut off,
forgetaboutit.... So I think some of the dampening is from the OEM parts, the balance from the cartridge. I am just a front tire and brake lever away from installing my 89 FJ/88 FZR front end... Can't wait....
But if you're installing them with anti-dive, I would think the A/D circuit would need to be bypassed or otherwise deactivated.
Also, I would hope the valves rebound was completely independent of the damper rod rather than relying on it for some effect.
Not trying to be negative here, I WANT a better fork action!
DavidR.
Nope, as mentioned the thin oil travels through the lower stock valving without any problem. The valve does all of the dampening and rebound internally but the orifice does need to be adjusted, if you have one, to the medium setting.
I tested them on my bike, A/D installed brake lines bypassed and on my wife's, fully functioning A/D and the function of the valves was the same. The valve does all the work before the A/D can come into play.
Randy - RPM
Quote from: soundmindryan on April 14, 2012, 11:52:17 AM
I believe the RPM required 5w fork oil is too thin for the damper rod to make any effect on damping and that is all facilitated by the cartridge. :scratch_one-s_head:
Quote from: FJmonkey on April 14, 2012, 01:24:14 PM
Quote from: soundmindryan on April 14, 2012, 11:52:17 AM
I believe the RPM required 5w fork oil is too thin for the damper rod to make any effect on damping and that is all facilitated by the cartridge. :scratch_one-s_head:
Having just installed a set, the instructions are to preset the dampener setting to the middle setting. Then with the rod cut off, forgetaboutit.... So I think some of the dampening is from the OEM parts, the balance from the cartridge. I am just a front tire and brake lever away from installing my 89 FJ/88 FZR front end... Can't wait....
mate im just a little green,, i was impressed when i swapped my 84 front for an 89 , you should be handling better than that again , think i better save for these valves seem to be a must have item
Hey guys, I finished up the project. It was a little intimidating the first time into the forks since that is new territory for me. And my only goal was the seals cause they leaked. I want to upgrade some day. I think someone had been into the forks before. These forks are just in poor shape, lots of pitting as well as poor surfaces where the seal sets in. (even after cleaning them up). The big disappointment was that when I removed the locating screws, only half came out but I didnt realize that. Prev owner must have sheared them off and screwed the old "Half screw" back in over the other half. So, when I used impact to loosen the large bottom bolt, the locating screw buggered up the bottom of dampening rod. Didn't have the tools or fortitude to try to get the broken screws out, they are pretty small. When I put it all together, I had to fight to make sure the notch in the bottom of the rod stayed straddled over the stub of the broken locating screw. I don't even know it these forks are worth rebuilding in the future. Oh, well, I guess I bought myself a little time. Glad that is over with!
Nice job. Thanks for the update. The '87 forks I took apart to use the upper tubes had the damping rod buggered up in the same way, even after I removed the locating screw first. I knew someone had been into them before as the tubes had "Forking by Frank" etched into the top tubes. I didn't have to use them since I used the original rods from my '89 forks. Once you get into the forks, you can see how simple they are. I was hesitant at first also, thinking there was some kind of rocket science voodoo inside them. Randy is right about the idea of once you have them apart, might as well install new bushings, as it adds NO further complexity to the job. Since I still don't have both my forks back together, I still may spring for the new bushings. There is a file in the "files" section that talks about shimming and dimpling the existing bushings. Anybody wanna chime in about success with that? :scratch_one-s_head:
Quote from: FJmonkey on April 13, 2012, 01:52:29 PM
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....
Sorry to add to an older thread, but yes, watch that damn fork cap coming off the tube. When I did my springs a few years ago, I though the weight was right off the front end, but oh no it wasn't. First fork cap I had covered with my weight on the socket pretty well ready to catch the little "pop" as it came off, but with the full weight of the bike on it, it shot off, whistled past my head and put a nice ding in my sheds steel roof. I sat down for a bit after that, thankful it did miss my head, phew!. (hate undoing spring loaded parts :mad:)