Special fork seals

[BigRed]

Hey, folks.

I've got the Yamaha shop manual, and I'm not impressed. The cover says it's good for my bike ('80SG), but the content only covers standards. I need to do my fork seals, so thought I'd post here for helpful tips and hopefully avoid posting later with problems

Do I actually need to remove the forks, or can I just take the wheel off, remove the allan bolt in the bottom of the forks, and pull the outer tubes off? If this is doable, then I can also put the oil in without removing the caps and having to deal with trying to thread a cap against the spring pressure.

I've done fork seals before on my Honda CX500. Basically, there was the allan bolt in the bottom, and a circlip holding the seal down, and I think that was about it. Is there anything significantly different about my XS11?

Thanks in advance,
Brian

[rpgoerlich]

You've about got it covered.
I still pull the cap sometimes to hold the damper tube if it spins, then remove it and the spring for inspection and cleaning.

[tinman905]

I have never tried it that way . I would think it might be a bit more difficult to put the fork oil in after you reinstall the tubes but it can be done. If it's the first time you have changed the seals in those forks you might want to tear it down just to be sure all parts or on the proper place and give it a good cleaning as there will be lots of crud in the forks.

[bikerphil]

If you have the front wheel off and the calipers, it's only 3 more bolts per side that need to be loosened to remove the fork(s). Break the cap loose first, then the 6MM allen bolt, then slide the forks out and service them. You can make a tool easily like the one below out of a notched 2X2 about 20" long for installing your air type fork caps. HTH

[tinman905]

Another good reason to completely disassemble is you can check your spring specs. You might get a nice surprise and find Progressive springs in those pipes

[Elevener]

If you dont pull your tubes off and the allen bolt spins, use a reguler ratchet strap and place one hook thru the caliper mount hole and the other over the handlebars. Compress the fork and loosen the bolt. Then save yourself the hassle of putting fluid in and remove the caps (loosen tree bolt first).

And save yourself the time, Do as bikerphil says and go ahead and break the saw out and notch a 2x2, or do as I did....be to lazy and fight the cap till your fingers hurt then go out to the truck and get the dam saw!

[fredintoon]

[QUOTE=BigRed;270096 - - - I need to do my fork seals, so thought I'd post here for helpful tips and hopefully avoid posting later with problems - - - Brian[/QUOTE]

Hi Brian,
Best you tear the forks down completely, there's most likely 30 years worth of crud inside them.
Note that the Standard and Special fork seals are DIFFERENT SIZES, don't let the pimply youth at the parts counter sell you the wrong ones.

[BigRed]

I'll be sure to take the forks apart after seeing how much crud was in my brake system. If I want this bike to last another 30 years, there's no point in procrastinating on checking out the fork innards.

I ordered my seals from PartsNmore, so hopefully they are indeed for the special. I'm also really hoping that they come in today. It's supposed to be a crap weekend, so I'd really like to be in my garage getting this thing up to snuff, but there's only so much I can do without parts. I don't really like taking the whole thing apart and then waiting to put it back together... it ends up getting expensive replacing all the parts that I put in a "safe place" never to be found again.

I'll probably do exactly as you say... fight with the cap for an hour, then get the damn saw. Try the BFI first, then clean up the mess after.

Thanks,
Brian

[motoman]

Take the forks off, take 'em apart and clean them properly with solvent. Blow every thing dry and re-assemble, and do NOT shortcut at this point and use ATF! It works, but does NOT create the correct dampening as it doesn't have correct low properties, then there's complaints blaming springs, etc. If your forks still have the stock springs, measure that the unsprung height is still within specs(most WILL be) and use fork oil. Mine were done last year(still had original seals), as one was seeping a bit. Being the 81standard it also has the air caps, which I have always kept at 5-11psi under normal load cond. even being a factory dresser. Over years of oil traveling through orfices they WILL enlarge ever so slightly(heat from friction causes wear, even in hydraulics), so I used 15w Silcolene fork oil(brand is opional, but us motocross racers, old and new know Silcolene works the best and longer), along with OEM fork seals. Any aftermarket seal WILL fail sooner, so weel worth the few extra bucks to use OEM no matter what brand forks they may be. JMO, and likely with care the new fork seals will outlast me. Just an old school tip: On our "old school" moto-bikes lacking good dampening, we used to drill and tap caps and screw in schrader valves inserting 5-10psi depending on track conditions for better dampening on compression, plus the extra bit of pressure created from the air pressure pushed inner lip of seal tighter against upper tube resulting in no-leaky.....JAT.