Clutch Issues - Not disengaging

[Seifer]

Hi guys, I asked this on the old forum but it appears to have vanished in the swap over.
My clutch doesnt disengage properly. I have a GSXR1100 but I believe the master cylinder is from a kawasaki ZX9.
The problem is when you hold the clutch down it is tough to get the rear wheel moving, a few hard pushes and it will start to turn a little more freely but no where near as free as it would if the clutch disengaged.
As soon as you get go of the clutch and pump the lever again the wheel goes back to being near impossible to turn.
I have bled the system and pulled the clutch out to separate the plates.
What is interesting is I taped down the lever over night, (I have one of those clear tubes with a cap as reservoirs), the next morning the cap on the tube had popped off and was leaking fluid out the top. The clutch had effectively pushed its way back out.
This makes me think the master has gone but is there maybe something else that could possibly cause this?

[Chase]

I'd look at putting on a proper reservoir with diaphram and re-bleeding. If air can't move within the system you will end up with a vacuum and the fluid won't move... think pouring out of a can without an air hole, or blocking the breather on your fuel cap and you'll get the idea.

[Seifer]

It would be nice if it was that simple but even with the cap off I have the same problem. Aren't reservoirs sealed anyway?

[Chase]

Sealed yes, but the diaphram moves with the pull of the fluid - without it the brakes/clutch will just lock on. Had this happen on a bike ages ago that had a small billet reservoir without a diaphram.

[Redmohawk]

They generally have a breather hole above the Diaphram to allow it to move. Could be bad seals in the master , but with non standard slave I'd be checking the Dia of the slave if its a bit bigger to make clutch feel a little less. Or travel may have got to close to edge of inside of cyl and chopped out slave seal a little ?

Pull it all apart and have a look see , easy enough to rebuild em.

[kiwi kdx]

is sounds like ur plates are sticking togeather, i know you said u pulled them apart,

but ur oil may be too thick???

[BANDITROD]

maybe the pushrod is bent

[Redmohawk]

We're not all like you rod some of us leave it for the misses.

[Seifer]

Might pull it all apart then and give it another going over. Cant hurt right... good thinking too rod and kdx.

[Benz]

I had a similar thing happen on the rear brake of my katana dragbike. The rear brake would lock up after a few applications, and I'd have to release the brake fluid via the bleeder to free the caliper. Turned out to be the piston in the master cylinder was not returning back far enough to allow the fluid to flow through the little bleeder/filler hole in the master cylinder, so the system was effectivey pumped up and locked, until I released the bleed nipple. Maybe that hole is partially blocked in your master cylinder....would explain the slow release of fluid overnight. You DO need to allow for air movement in the reservoir, otherwise a few applications [a hot engine will expand the fluid a bit too]will pressurise the system, and the only release will be the little cap popping off.
It could also be the slave cylinder is partially seized.

[mr.zxr]

have you checked the clutch basket. i had he same problem and it was the basket. it had little dents where the teeth on the clutch platesmake contact with the basket.(if that makes sense). Basically when you pulled the clutch in the plates would get stuck in the grooves and not disengage fully. i just filed them smooth and it worked again.

[Seifer]

Ok ive rebuilt both the master and slave and have replaced the reservoir. Ive got good strong pressure however the clutch problem hasn't gone.
Before I rip into the clutch assembly itself, i believe stock master is 14mm, mine is a 5/8 or 15.8mm.... will this make a difference that is noticeable?

[BANDITROD]

i reckon mr zxr might be onto something..... did you check the pushrod

[Seifer]

Yeah the rod appears to be straight. No worries, ill pull her all apart tomorrow and have a looksie inside.

[jmw76]

I have run into clutch problems in the past.
I have experienced the pits in the clutch basket as explained earlier, but this usually resulted in slip and not binding up.
A release failure has usually been as a result of some hydraulic issue and not getting enough travel at the clutch end.
Your slightly larger master cylinder should give you more travel, not less.

Be interested to hear what you find.

[Seifer]

One other question before I pull it all apart, how many clutch plates should be in there and what is the order for the plates, ie fibre or steel first. Its possible there may be one too many in there or not enough. Also with the diaghragm springs, which way do they face?

[BANDITROD]

curved side out from memory

[Seifer]

The main reason why I ask about the plates is because my Haynes manual suggests putting in a friction plate first and the alphasports.com diagram has a steel plate in first, so which one is correct. Im not sure which one I followed when I put it back together so id be happy to admit that there is a plate out of place or a plate too many.

[jmw76]

The easiest way to work out the plate order is to start thinking from the centre hub bit first. It must have a friction plate against it (fibre plate). I am not sure whether the number of plates varied between early (coil spring) clutches and later (diaphram) clutches for the 1100. I know that I have read somewhere how many plates should be in the clutch but just can't find it currently.

As for the way the plates go in, I am pretty sure that I instal mine with the rounded edges facing inwards. This allows for the plates to slide more easily in the basket on engagement and minimises clutch slip.

If you have too many plates installed, it will cause clutch bind. I recall doing this once in error.

Peter.

[Seifer]

Well i had the right amount of plates, i thought i might see if it was my oil so i degreased them and put them back in. Sure enough the clutch is now operating properly. My oil must be too thick as id previously taken it apart and reoiled them. I'm only running 10w50 I think.... Odd.

[BANDITROD]

well thats strange what brand oil are you using

[Seifer]

Penrite

[BANDITROD]

mmmm i have always used motul in my bikes but i have never heard any bad rep about penrite either .....oh well at least you got it sorted mate

[Seifer]

Which number do i need to lower, the ten or fifty

[BANDITROD]

well i use 10w40 in my bikes mate

[jmw76]

I have successfully used Motul 5100 10W-50 in my race engine for years. Never had a reason to suspect it was responsible for clutch drag. We are living in Australia and not the south pole so the heavier oil should not be an issue for you.
More reently I have been running Penrite Racing 10w - 40. Clutch slip is usually the complaint when usihg oils with lots of anti-friction additives (car oils).