Help wiv me clutch ???
 

My clutch slave cylinder went pop the other week...so I got a nice STM one from Cornerspeed. So far so good.

Except. I can't get enough clutch actuation out of it to disengage the clutch fully. I've bled it until I'm blue in the face using all types of tips and tricks suggested by the lads on Sunday's rideout and I haven't seen a single bubble in the fluid for ages, but full actuation is still not happening.

When I first put it on the bike and bled it through the clutch lever locked solid and I mean "can't-budge-this-thing-a-millimetre" solid. That would indicate to me that with absolutely no sponginess at the lever there was no air in the lines or the master/slave cylinders.

The reason that the lever went solid was that my bike was registered in 2001. The instructions said to use a pushrod spacer for bikes up to model year 2000, but I left it out because I didn't think I would need it. What this meant was that the slave piston pushed out far enough to meet up with the casting boss where the actuator rod goes through, hence the lever locking solid. So, I put the spacer rod in and it all worked - up to the point I've mentioned. Now it seems that the spacer isn't quite long enough because the full travel of the piston still isn't enough to disengage the clutch.

Any ideas :puzzled::puzzled::puzzled:

I am sure Nelly will have an answer.

He should be back from Assen now .

Jools can you wind the span out at the lever so you effectively have more travel to push the rod further? not a fix by any means but at least get you moving.

Isn't this a common issue with over sized slave cylinders as they are bigger thus need more fluid to push the pushrod as far as before?

Jon, if Jools ST has the same lever as my old ST there is adjuster on the lever.:o

Nelly is back at work tomorrow ( Weds... )

don't over size cylinders need a longer push rod

ST2's dont have adjustable levers as standard.

Mine has span adjustable levers, and I can tell you they've been set at all positions, they give full travel of the master cylinder wherever they're set.

but I'm seriously wondering if that spacer is long enough. Keefer may be right in that a longer rod is required (no s******ing). I've taken the slave cylinder off and just squeezed it between my thumb and forefinger as I gently pulled in the lever. The slave piston moves about 4-5mm, surely if the actuator rod was being moved that far the clutch would disengage :puzzled:

All I can think of is that the piston is traveling a couple of mm before it engages the actuator rod. Anyhow, that's enough for today...another half an hour of that and the toys would be out of the pram

Can you not put something in the pressure plate that's a few mil longer just to test?

Ta mate...tomorrow now though...I can already feel a Stella or two coming on after struggling with the thing for another hour today (on top of the four hours on Saturday)

A ball bearing is a popular mod i think.

Jools,

Dave @ Casoli had to make/modify a spacer for my ST4 when he fitted an Evoluzione slave - as I was having the same problem as you are now.

As to pre 2000 models - I've found that there's quite an overlap as to when they actually imported bikes with the later crank cases (as I found out when changing my nuetral light switch), so yours may still be the earlier type engine as mine is.

So..........a different size spacer may well be the answer!

Good luck with it mate,

Lee

Jools

Had a similar issue on my 996 a short while ago...

first of all the slave seal went - sorted that out with a standard kit.
I also had judder off a nearly new lightweight clutch/plates setup. (even after numerous cleanouts and an open cover).

after a few calls with JHP - it was suggested fitting 2 dished plates to the clutch pack, mine at the time were all flat and the stack height was spot on.

Fitted both dished plates in and ended up with no clutch (impossible to get neutral) - so have now just got one dished plate in and I can just get it in neutral (sometimes).

I did consider also fitting a larger slave but at the time heard I would loose travel on the clutch so avoided it.

...reading this back it probably won't help you at all, might help someone else out though.

regards
les:)

Jools mate,haven`t read all this thread,but the STM you got off Nelly did it come with a little bullet shaped piece in the box?You need this to extend the length of the rod on some models,as for bleeding it shouldn`t be a problem unless you`ve let the fluid drop to low in the reservoir.