View Full Version : Sv1000 K3-N more forking questions
I have recently re-seated my fork oil seals using a home made fork buddy which means I am no longer losing oil from down there. I also replaced the dust seals as it looked like it was these disintegrating generating the crud that got into the main fork seals.
It seems however than in sealing that leak I've now moved the problem to the next weakest spot which is the fork caps. I sent the forks off to have the oil replaced last year towards the end of the season and one of the caps leaked a bit when I got them back but after nipping the cap up a bit it seemed fine. But it's now started leaking again. Tightened it a little more but still leaking.
Couple of questions for those who've worked on the thou forks or have one to hand to look at.
1. If I get the front end up in the air to unload the forks, how far will the fork cap try and spring up when undone? Am I fairly safe just taking the handlebars off and using a 12mm socket on it or am I likely to end up with a cap/socket shaped dent in my face?
2. Under normal circumstances should you be able to see the top cap o-ring when the fork is all together? I can't see mine so am wondering if it went AWOL during the oil refresh and that's leading to the leak.
I suspect I've mangled the o-ring when over-tightening the top cap so will hopefully be able to get a new one and fix it. I am however quite surprised that oil ends up close enough to the top of the fork under normal situations to leak anyway. Maybe it's just residual oil at the top from when I had them at all sorts of funny angles when I changed the dust seals.
Any advice?
Just a quick bounce before I go and take stuff apart.
1. Should you be able to see the rubber o-ring on the top cap thread when it's done up right.
2. How aggressive is the top cap release if you've got the front end raised up?
Cheers, Mark
no you should not be able to see the top cap oring when the cap is tightened down. if you can then it suggests to me that it has come loose (very very doubtful) or more likely someone had crossed threaded the cap (bye bye cap if that has happened) or it was not done up properly after a last service.
if your taking the forks off then loosen the top yoke pinch bolts first then loosen (just loosen dont take off) the top caps while still in the bike
on SV1000 there is no spring pressure as its the cartridge that holds the spring. if you are replacing seals you need to remove the spring to be able to bleed the cartridge.
I'm just looking to stop it leaking out of the top cap. As main seals are now not leaking (at least not after last ride) I loosened the top pinch bolt and gave the cap about an 8th of a turn to tighten it but it's still leaking. I'm surprised much oil makes it up to the top given there's an airgap. How does it continue to leak from the top? Does it move around that much or is it likely to be just left over from when I had everything upside down the other day?
Not sure if I've now over tightened it and mullered the o-ring or just need to torque it up some more. Last time was just a ring spanner on the cap but to torque it correctly I need to take the bars off to get a socket on the bolt.
Knowing it's not going to leap up and smack me in the face is one less thing to worry about.
Current plan is take the cap off, check o-ring is good. Replace if not, just clean and rotate if it's OK then torque it down correctly.
Update and seeking more advice.
Right then..... Main fork seals still not leaking. New dust seals look pretty. However still leaking oil out of one of the top-caps. Fork bounces up and down so clearly it's got an air gap. Maybe not the right air-gap, but it has an air gap.
I took the top cap off and the o-ring looked in good condition and no signs of grit or chewing up . Cleaned it all up, torqued it down to the correct torque, put everything back together again and it still leaks. Have ordered a new o-ring but not convinced it's going to make a lot of difference.
Significant problem is that working on the forks requires me to work on them together as the mudguard is pretty much welded on.
So without too much grief, if I wanted to check the oil level, how would I do it with a fork leg full of springs and other gubbins you are supposed to take out to fill them up? Does anyone know the oil level of a correctly filled leg with all the gubbins fitted but the wheel unloaded or some other measurement I can take without stripping the internals?
Also, When you take the top cap off it only lifts a couple of inches then hits a lot of resistance. It feels like if you pull and twist and pull and twist it will eventually some all the way off but not sure if this is correct. Are these symptoms of bigger fork problems or is the top cap effectively held captive by the preload mechanism?
If I just take out a few syringe-full of oil and see if it still leaks, any idea what that would do to the handling while out for diagnostic rides?
I feel I'm getting out of my depth a little. Maybe just keep a cloth wedged in the headlamp and wipe oil up until it stops leaking out.
simple answer to the oil level, you cant.
i think you need to find out where the oil is weeping from. my suggestion is to clean the top with brake cleaner then dust some talc on the top. go for a ride then see where it has a damp mark as you could be weeping from the top preload/rebound.
there should be no movement in the top cap apart from going round and round to tighten/loosen. the cap is connected to the damper rod which in turn keeps the spring in place.
my advice is to bite the bullet and get the mudguard off and do the job properly.
on cartridge forks you cant just pour oil in as the cartridge needs bled which involves removing the spring. the oil level must be checked without the spring plus the cartridge, tubes bled and positioned upright. all this involves special tools and knowledge if you dont have these then you might as well be pizzzing in the dark against a strong wind.
i'm not trying to be rude or nowt but if you dont know what you are doing then you can do more damage than good.
I'm definitely right on the edge of making matters worse. Top of the preload adjuster is dry. So it is either coming up from the outside of the pre-load adjuster and running down or seeping out from the top cap and going up.
I'm hoping the new o-ring and correct torque will do the job. Best part of £5 for a 25p o-ring!!! Unfortunately it's thinner than the ones I've got hundreds of that fit other things :(
If it still leaks after that I'll try dropping the oil level slightly to see if it changes the leakage. I can't imagine dropping the level by an inch or so will chuck me in a hedge. But after that it's time for a grown-up to at least get the guards off which gives me options on messing with or sending off a fork in a more accessible condition.
dropping the oil level is going to do nothing for it leaking. the oil gets a fair old swishing about in there and its also put under pressure. TBH i think its the orings on the rebound adjuster/preload
Can they be got at without a loud boing and need for special tools?
nope as you need to take the cap off the top of the damper rod. the rebound screw is actually a big long needle that goes all the way down the inside of the damper rod. when putting the cap back on the damper rod you need to set the rebound adjuster hight so it sits properly above the rebound bleed hole on the valve.
i hate to say it Mark but if your trying to save money your going the wrong way about it, a shop would have charged you about £120-170 ride in/out and for that would have sorted the seized mudguard bolts as well.
dont you have any mates with the proper tools that would help you out?
Unfortunately I don't know anyone locally with the skills, tools and patience to drill out the guard bolts. I did pay an "award winning" Suzuki mechanic to service them while joined together as he wasn't convinced he could get the bolts sorted without a lot of effort. I'll go see my local engineering firm to see what they can offer. Problem is round here there are lots of people with bikes and loads of money so bike mechanics pick and choose what they do and charge you plenty for a mediocre service. A few thousand cashed up bike riding transitory squaddies mean repeat business is not their prime concern!
I'll try the new o-ring and if it still leaks I'll get them drilled then find a good fork bod to set them up right. Mark at MH racing comes highly recommended and does a postal service but was going to be tricky posting them joined together.
Thanks for the advice to date.
UPDATE:-
Took the bike for an MOT and the tester reckoned my forks were firmer than his track bike. So back to basics....
Took off the leaking top cap, found the o-ring to be in good nick. Torqued it down correctly, made everything oil free and talc'd the top to see of it came out of the pre-load or the top-cap seal. Nothing came out of anywhere, so either it's fixed or has now run out of oil.
I then had a bit of an epiphany ref the settings. Last time it was twiddled with it had dishwater fork oil in it. It now has oily oil so will be wrong. Dug out the manual to set things back to standard.
Pre-load was set to 4, standard is 7. Damping was set to about 1/2 turn out, should be 1 1/4. Rebound was as per spec; well one was and the other was seized so working assumption is that that one is also standard.
Reset all to standard and now it actually sags when I sit on it and the bike goes down pretty much flat when you press on the join of the seat and tank. Neither conditions existed prior to resetting.
Test ride felt a lot better and still no oil leaking.
Need to get the feel of it again then perhaps do a bit more damping and pre-load adjusting once I've got used to it but for now I recon we're in a much better place.
When I get another pass I'll work through this guide again to tune it to oily oil.
http://www.gostar-racing.com/information/motorcycle_suspension_set-up.htm
PS, Bibio, Just saw your PM. Thanks for the offer but I think I'm OK for now.
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