Fork Replacement

[TGTwin]

Around 11,000km ago (6 months) I got my fork seals replaced at the local bike shop. Couldn't do it myself as this is a 2006 GS500 with the Spanish (I think)-made forks that need a tool to be able to undo the bottom bolt to pull them apart.
The shop noted some pitting in the chrome, so they also reground the stanchions for a better seal.

I jumped on the bike this morning and noticed a whole bunch of fork oil under my wheel. The right-side seal must have failed while riding home from work yesterday as there was no leak before this morning, and there isn't any evidence of a leak where my bike was parked at work.

Considering 1. I can't pull these forks apart and 2. this is the second time the seal has failed, I was thinking of getting new (to me) forks completely but finding GS500 forks where I live in Australia is difficult. Has anyone used forks from a different bike to replace the ones on the GS? I know there is a wiki article about putting katana forks on the 500 but I can't find those either.

[gregjet]

Where are you TGTwin?
Possible the seal around the bottom bolt was left off or was stuffed and put back in. It may even just need tightening unless you can see where the oil is coming from around the main seals. They are hard to tighten properly so they may have thought it was OK tight but has squished down is is now loose.

[TGTwin]

I'm in Brisbane, Australia, and once you factor in shipping large parts like forks just cost too much to justify on an old beat-up GS.
It's definitly leaking around the main fork seal. I can see it oozing out of there, and it collects on the front guard/wheel/brakes.
It could be that the seal just needs replacing (the bike was out in the weather for a few months until I got our new house, no it's garaged) or some dirt got in there or something. I'm hoping the stanchions aren't pitted out or anything. I can't see anything above the waterline so-to-speak, but haven't lifted the dust seal yet to have a good look.
Either way, I had no luck last time getting the forks apart. Going to try it now with an air impact wrench now that I have my workbench/vice/etc available to me again (I didn't 6 months ago).

[Endopotential]

I have a 2007 F.  Maybe your fork is like mine, and this trick will work.

Just a shaved down broom handle to wedge into that bolt, to secure it while the hammer drill does the work on the other side.

http://gstwins.com/gsboard/index.php?topic=70830.msg851128#msg851128

[The Buddha]

Way back when I actually bothered with stock GS forks (including send a pair to lindemann for their ridiculously cheap by today's standards but a whopping $200 in 1995) ... well it was later than that, 2004-05 time frame that I found the copper bushings that actually the legs slide in have a moly/Teflon coating. I found a place near charlotte NC (Nascar country) that would re coat them with a similar but better coating that will take in and retain oil. They said they can coat them thicker and usually that seals up an iffy fork.

I never went through and did a GS set, I did a few katana sets and then as it was too much work, I gave up on that too.

Could be worth looking into for you maybe.

Cool.
Buddha.

[J_Walker]

Who needs fork oil, just run ridiculously stiff sonic springs, and forget the oil. 

[gregjet]

TGTwin I am just up the road in Bundaberg.
Possible you had a dud seal or that the circlip wasn't seated properly. One one of my racing CBR250RR's I had a seal die after 6 months of racing ( ie not very many miles). It was a cheap set of aftermarket seals, but I can't remember the brand. Replaced them with another brand ( should have bought the Honda ones as it happens as they were actually cheap).
If the bushings are badly worn or the wrong size it will wear the seals faster as well , but a 2006 shouldn't be in that boat.

Always possible you have a bent leg. Does it pull to one side under braking at all?

[TGTwin]

Well, I pulled the dust seal off today and think I found the problem:

Looks like water (from when it was parked outside most likely) has rusted the seal. I can see rust on the top retention clip thingy, so I'd say there is further damage underneath.
Can't see any major pitting/gouging on the stanchions though, so small victories. Time to order some seals, then try an impact wrench on the thing to get it undone.
I tried the broomstick-in-the-end last time this happened, but didn't have any hammer drills/impact tools so was just using hand tools. Didn't have enough of the sharp impact I think to get the job done.
On that note, is it easy to re-do the bolt when re-installing it all? Is spring pressure from the shock spring enough to stop it rotating and get the bolt tightened up?

[The Buddha]

That rust is the clip, not the seal, and its not enough to cause a problem. And how in the world does it get there past your dust seal ? OK that crap has likely cracked. So OK do seals. But done be surprised if that thing still leaks, and do those bushings and maybe it will seal up better .... No clue, never dod that except to a kat FE and those things hold up extremely well anyway.
Cool.
Buddha.

[TGTwin]

Always possible you have a bent leg. Does it pull to one side under braking at all?

I don't think the leg is bent. I haven't noticed any strange behaviour under braking, and this issue has really  gone from "not a drop of oil at all" to "pissing out all over the place" in the place of a single work-to-home ride.
I'm hoping that I just bought shitty seals, or the shop installed it slightly wrong, or something along those lines. Going to buy another set and have a go replacing it. I figure another $30-odd dollars is cheap enough to try first. Otherwise it's replacement forks, and who knows where I could find those for any decent price.

[gregjet]

When you get it apart I'd be checking the slider bushes aren't too worn.
Also double check there wasn't put too much oil in them. When they hydraulic lock, the oil has to go somewhere if it can and it can blow the seals.
Still there are some crap fork seals out there ( personal experience)

[Bluesmudge]

Sometimes you can clean out the fork seal with a cut credit card or purpose built piece of plastic and the seals will work again.

The shop may have used cheap seals that known to not last long. K&L have worked great for me and I think its what Suzuki uses anyways.

Check for pitting on the tubes. Last time I replaced seals I hit the tiny rust spots with some 2000 grit sandpaper to make sure there were no sharp rusty bits.

Also, can confirm the wooden broom handle trick works. Better than the actual Suzuki tool apparently. It just takes time finding the correct shape.

[TGTwin]

Well, I bit the bullet and replaced the seal on the weekend. The fork came apart a lot easier than expected, just spring pressure and hand tools let me undo that bottom bolt. I reckon that is because they were only done not too long ago.

Anyway, the stanchion looked perfectly fine, and even the seal itself looked fine once I got it off. I did see a small strip of loose rubber come out with the seal (I think it flaked off of the dust seal) and I think that had jammed against the stanchion and sealing lip of the seal. This would explain the sudden gushing of oil.

In hindsight, I probably could have gotten away with using a "SealMate" tool (or piece of plastic cut into the same shape) to wedge under the oil seal and clean out any debris and it would have fixed the issue. Oh well, a learning experience is never a bad thing.
At least I don't have to buy new forks 

[J_Walker]

did you do this? just wondering, I never hear anyone talk about replacing these two things on forks.

[gregjet]

Oh Ghost who walks,
Those are the bushes to which I have referred. If they are worn even a tiny bit the forks end up sloppy and gape at the seals under load. Not dear to replace if you have the forks apart.

[J_Walker]

Oh Ghost who walks,
Those are the bushes to which I have referred. If they are worn even a tiny bit the forks end up sloppy and gape at the seals under load. Not dear to replace if you have the forks apart.

Hmmm interesting. but manual doesn't seem to provide a "spec" for measuring them to check for warn-ness

[gregjet]

Depending what they are coated with , they are usually several VERY thing coats, usually copper and something like teflon or bearing metal over that with steel bush base. When they wear the lower layers show through.

[TGTwin]

I didn't happen to replace those bushes, so we'll see how it goes.
If it starts leaking again I'll know where to look at least.
I'm just happy to have front brakes again. Apparently pads don't like being soaked in fork oil.

[The Buddha]

Those bushings - well the guy was lightly sandblasting them and coating them with moly-Teflon that would be thicker and hence hold oil better and sort of nicely swell up.
Cool.
Buddha.

[ShowBizWolf]

After I read this thread, I looked for more information about those parts J_Walker mentioned, since I'm getting ready to finally do my front fork project.

My Clymer book says, "14. Inspect the slider (A, Figure 103) and fork tube (B, Figure 103) bushings. Replace them if either is scratched or scored. If the Teflon coating is worn off so the copper base material is showing on 3/4 of the total surface area, replace both bushings."

I wonder if it means the inner surface or the outer surface or both ? Anyway...

The "slider" is the taller one... F in the picture Walker posted and the "fork tube bushing" is the shorter one... E in the picture.

I also remember reading or hearing somewhere that if you're gonna remove the "slider", you should replace it with a new one, rather than re-installing the old one. It's gonna bug me until I remember where I picked up that bit lol.

I ordered 2 new OEM sliders and 2 new OEM bushings. I don't have old sliders for pics because I think they are still on my old bent fork tubes at my dad's garage... but I do have the old bushings from my forks to show the difference between them and new. The new parts have this really nice black almost velvety coating on them with shiny polished edges.

Old bushing:


New bushing:


And side by side since my above pic isn't that good lol: