BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

Just replaced C.S. cylinder on my 02 R1150R (18k), do I also need to replace the clutch?? Doesn't seem to be slipping much at the moment.

BCBlueR wrote:Just replaced C.S. cylinder on my 02 R1150R (18k), do I also need to replace the clutch?? Doesn't seem to be slipping much at the moment.

Slipping much? So it is slipping?

Was the clutch lining contaminated at all with fluid? If so you might want to consider replacement.

"Much"..... sorry wrong choice of words. Dealer did the work, no mention the clutch being contaminated....but I harbour doubts. Can you have a leaking slave that does not affect the clutch plate?

If it's not slipping and with that low of mileage I don't think I'd worry about it. I would have to think the dealer would have tried to sell you a clutch if they at all thought it had a problem. I would expect 100,000+ miles before a clutch would be necessary (depending of course on riding style and habits). To answer your question I believe you could have a leak and not affect the clutch lining. If your leak had been there a long time and got severe it could get to the clutch lining. I say all this with a slight amount of uncertainty. I'm not a real authority on the clutch. CycleRob would be the expert on this. Possibly he may see your post and chime in.


I'd be more concerned about making sure you keep the antifreeze levels checked in the tankside radiators.

If you have my old bike, it would be leaking without damaging the clutch plates, because Cyclerob drilled a tiny drain hole in the bottom of it so if it DID fail and leak, it would exit to the outside and not flow over into the clutch housing. You can also cut a narrow gap out of the downward area of the gasket and it will provide the same insurance.

BMW engineers placed a small felt sleeve on the clutch engagement rod to keep the fluid from crossing over, but it fails as often as not...as many can attest to.

That is something the slave on these bikes should have had designed into them from the factory. Rob is very good at correcting little design flaws like this, when he notices them.

Ahh yes, the slave cylinder. It has a service life that turned out to be shorter than the cable operated clutch release on my 1990 VX-800 Suzuki with more miles, and went to the BMW dealer when I traded it in for my `02 R1150R. The slave assembly was also a $128 BMW dealer replacement part that literally never, EVER needs replacement on Japanese bikes, regardless of their age. Here's what I found when I had my OilHead apart to clean-n-grease the clutch input shaft splines:


The next 2 thumbnails take you to one of the slave mods that they are talking about, this one created on the rear of the transmission casting.


A leaking slave unit is not as bad as the transmission rear input shaft seal leaking oil. That's because the DOT4 fluid usually leaks at a very slow rate as the seal wears out -and- the DOT4 fluid leak usually evaporates from the engine heat before it can travel far enough to leak on the clutch disk. The leaking transmission shaft seal oil does not evaporate and it will be more likely to make it's way to the clutch disc friction material.
FYI, The slave can be removed after you remove the rear wheel for better access. There are no individual replacement parts, you have to purchase the whole unit. The moving/mating parts always damage each other, so that all-or-nothing policy is not really a bad thing. Be aware, the slave R&R is not an easy job for the inexperienced or the impatient.

To go to a very thorough clutch master cylinder and slave fill/bleed procedure, go here: http://r1150r.org/board/viewtopic.php?f ... 82#p251882

I'm glad the F800 has the inexpensive cable operated clutch release. It works with little effort and very smoothly, with just ONE free-play adjustment in over 30,000 miles (48,280 kilometer).

Edit: To add MC and slave service link and UpGrade photo provider away from photobucket to Postimage.org

yeah, i really don't get hydraulic clutches. what for?