1981 XJ650 fork seals

I recently bought an 81 XJ650. The bike is mint except for one of the fork seals leaks a little bit. I ordered some factory seals from the dealer. Has anyone who has done this before have any tips or important things I should know about changing out the seals? Any special tools required? I have a Haynes manual for the bike that gives a vague description of how to change out the seals. Any help is appreciated.

Thanks

 

Welcome to the forum Mitchhill, your in the right place. I've rebuilt several of the 81s forks and they can be a bit intimidating at first. Tools you will need: an impact gun (OPTIONAL, you can do this by hand but this is way easier, electric or pneumatic), a bunch of 3/8" extensions, an 8mm (that or 6mm, can't recall which your bike needs, but you should have both regardless) allen wrench, couple of small screwdrivers (to pry out the seals and retaining rings), and a bolt with a 17mm head (or is it 19? can't recall, you will see this setup in your Haynes, it works and is cheap).
That ought to do it. Also use 15 weight oil at least, not the 10 weight specified. The front end on these bikes tend to be really soggy.
1. Read the fork section of your book, become familiar with the parts, their location and function. I would follow their instructions in the order they specify.
2. Drain the oil out.
3. (one assumes you have already pulled the front tire and axle at this point) Note: MAKE SURE THE BIKE IS SECURELY BRACED AND CANNOT FALL OVER!! You must pry out the rubber cap at the top of the fork tubes to access the seal caps.
3. Push down on this seal cap with some form of rod or drift (preferably brass or something non marring that won't puncture a hole in your hand). This may take some effort which is why your warned to brace the bike. There will be a thin circlip that must be fished out of it's groove above the seal cap in order to pull the cap. This may be a bit of a challenge by yourself so source a buddy before hand. The circlip may also be rusted into place so be sure to have some breakfree handy to soak it. When the clip is removed you should continue to maintain pressure on the cap since it is under pressure from the spring. SLOWLY ease the cap out and capture the parts.
4. Pull out the spring noting the orientation of the spring.
5. Hit the allen bolt on the bottom of the stanchion with the impact and it should release. If not you will need to whip up the stack of nuts mentioned in the book and drop it down the tube to lodge in the bolt. Here is where you will need all those extensions. Use an appropriate number of extensions to get a socket down on the nut/bolt tool to hold it in place and, while holding this, spin out the bolt on the bottom of the fork leg. You will have some dripping so be sure to have a catch basin of some sort in place. Invert the fork and let the piston assembly drop out into a rag or your outstretched hand.
6. Pry the dust seal at the junction of the slider tube and the lower fork body. It will take a little time and patience but it is doable with a very thin bladed screwdriver and a little finesse.
7. Pry out the seal retainer clip. In practice I've found most of them to be rusted out so be prepaired to replace them. I used an appropriately sized internal snap ring as the dealer wants darn near $13 a piece for those stupid clip (as compared with less than a dollar a whack for the snap rings).
8. Pull the fork tube up, using it like a slide hammer, to dislodge the old seal.
9. Clean out the tubing and lower assemblies.
10. Lubricate the new seal and slip it into place. Replace the clip. (easier if you install the seal first and insert the tube through the seal, but be forwarned, the lip may roll under on you so watch out!)
11. Reinstall the dust boot.
12. Insert the piston assembly back down the tube in the correct direction. Insert your tool to hold it and tighten the lower bolt to spec with a little daub of locktite.
13. Pour the specified amount of fork oil back into the tube.
14. Insert the spring in the correct orientation (as noted earlier).
15. Muscle the sealing cap back on top of the spring and thread it back into the tube (this is the hardest part, help is invaluable here).
16. Reinstall the rubber cap. Your done!

Good luck to you on this task, it isn't the easiest but it sure isn't the hardest either.

 

Thanks for the info. I shall try it this weekend.

 

What quantity and what oil do you think we should use?

 

Assuming you have the 81 H model such as mine, you would need 262 cc per fork of 10W/30 motor oil or 10 weight fork oil. If you have the J model, you would need 278 cc's and the RJ and UK versions would use 236 cc's. This is quoted out of the Haynes. I have posted all 650's since we have an international audience and your particular model wasn't mentioned in your post. I personally run 15 weight fork oil in mine since the stock setup is a little soft for my tastes. I've run as heavy as 20 without any problems. Maxima, Castrol, BelRay, PJ1, Torquo, and many others make good oil so you have a wide selection to choose from given your location. I don't have a favorite fork oil brand yet, everone gives me their left over bottles when they transfer and I haven't had to buy any in over 15 years! I just use what I have stored. I'm currently running a mix of Maxima 10 weight with Torquo 20 weight and I'm hoping it is something close to 15 weight by volume. The PJ1 is neat stuff as they add a molybdenum (MolyB to you grease freaks) formulation to their oil. It looks used straight out of the container but is good to go. Hope this helps and that you have gotten your seals done. Magolo, did you get the pictures I sent you?

 

Im changing my fork fluid and I cant get one of the spring seats to pop out the top,i have an 80 xj 650 btw, the other one came out easily..is there a trick for unsticking it?

 

It took me 9 months of trying before another forum member suggested Kroil: http://www.kanolabs.com/google/

It worked when nothing else did. One tip: DO NOT hammer the plug down in the tube any further than just to clear the ring clip; the inner tube is tapered and you can jam the plug.

Also, loosen the upper fork tube clamp bolt, it can sometimes contribute to a bind on the plug.

Two additional tips for rebuilding forks: It's much easier if you remove the forks from the bike altogether and work on them individually; and you can use a spark plug socket that has a 19mm hex cast into its base, flipped over, on a bunch of long extensions to hold the inner damper tube.

 

Hi Robert -
I know this is an O L D thread, but I'm working on this same project and had a question for you about your post if you're still around (or anybody can answer). I got the the retaining rings out today, and was expecting the seal caps to be easy to remove since they are springloaded. However when I slowly released pressure off of them (so I could get the circlips out), they didn't come out! They went back to their original position, but not far enough out of the tube so I could grab them with my hand. I was expecting the springs to push them beyond the top of the tube so I could grab them with my hands. Instead, they are BELOW the rim, so I can't even grab them. They did rebound a little bit so they're not stuck or wedged in. They might or might not be free in there. I wish I had a strong magnet to see if they would suck out that way. But I can't understand why these caps, which are springloaded, didn't just pop out. Any ideas?

1) The circlips are definitely out
2) The bike is on the center stand, but still resting on the front wheel. Not much pressure is on the wheel as I can lift it no problem. Any reason why it would need to be off the wheel to get the seal caps to protrude more?

Confused....

 

The pinch bolt on the upper tree clamp is most likely applying pressure against the fork tube keeping the cap from comming out. Try loosening the pinch bolt.

If the cap still refuses to come out. Try cycling the fork.

Warning!! Do not stand over top of the fork while releasing the pinch bolt. The cap could shoot out with some force. It would be a good idea to place a heavy rag over the top of the fork to provide a means of retaining the cap in case it should go flying.

Ghost

 

I think I tried this already. is the pinch bolt just the clamp type assembly at the top of the fork stanchion? 12 mm wrench? I loosened it, still no go. It's weird because the cap bolts still move when I push down on them and they spring back but they stop, like they're bottoming out on something. But the circlips are definitely out. I only tried the pinch bolt on the left side of the bike, but it was all the way loose. If we're talking about the same bolt, but I can't reckon what else you'd be referring to.

 

That is the correct bolt.

Have you tried spreading the clamp with a screwdriver, or similar??

Ghost

 

I just tried to spread the clamp. It's a piece of plastic and I gently pried it open, but nothing. Didn't want to pry too hard in fear of breaking the plastic. I'm attaching a picture of what it looks like I'm trying to take off. I can't understand why this cap isn't just springing out. The circlips are removed what the heck is going on? It's the same on both sides.

It doesn't seem rusted tight either because I can push it down with good action and it springs up nicely but just stops like its hitting something. Any ideas? What is the damper hex bolt on the bottom of the spring? Do I need to mess with that?

 

It's not plastic, it's aluminum. Still don't want to pry too hard on it.

Probably a ridge of corrosion from the circlip catching the cap. First thing I'd do is support the bike - when the caps come off the nose will drop with possibly results you don't want.

Put some penetrating oil on them (Bigfitz swears by kroil). Then take a punch and a hammer and repeatedly tap them down a bit and let the spring kick them back up. They should eventually worry themselves out. Don't bang down on them - they can get stuck if they go much below their normal position.

If that doesn't work you can try removing the fork and compressing it with a bar clamp. The extra spring pressure might do the trick.

I know one more trick, but it is a next to last resort.

 

OK, thanks for the reply. I'll try it. Kroil is good stuff. stay tuned....

 

Got em! Thanks for all the help

 

im trying to get my top cap out on my 82650j and am having a similar problem. My cap bolt isnt moving at all though. I got it down just enough with a bar clamp, and pulled the circlip out, and it wont move up or down at all. the top of the cap is just above the bottom of the ridge for the circlip, and comparing it to the other one, it doesnt seem like its the whole way down.

ive pulled out the air valve, turned the fork over, and cycled it repeatedly until it bottoms out. and ive tried tapping it in a little bit. it just doesnt want to move...

 

ive also tried wrapping the leg in question in a ratchet strap and cranking it down and using the pressure so i can break the retainer bolt loose, to no avail...

 

Top caps that won't come out are usually hung on a nice neat ring of rust.

I fought this fight; X 2 bikes.

NO PRODUCT OUT THERE would work. You name it. Liquid Wrench, PB Blaster, JB80, CRC, nothing.

Then a forum member suggested Kroil: http://www.kanolabs.com/google/

Through Harbor Freight, free shipping: https://secure.cnchost.com/kanolabs.com ... r_hf.shtml

 

it really makes that much of a difference? ive always treated those sprays as one in the same. its been soaking in both pb and liquid wrench. ill see if pep boys has kroil though. i like to avoid harbor freight.

 

+1 on Kroil for working on those fork tubes. It's the only thing that gets into the rust and breaks it down enough to get those apart.

MN