Clutch Slave Cylinder
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Clutch Slave Cylinder
Based on what I've seen on CycleRob's post, this needs to be replaced. Why would this happen with only 4000 miles? I'm beginning to think BMW's are really crap. At least all my spines seem to be in good shape.
Re: Clutch Slave Cylinder
From what I know, I'd certainly agree.
But 4k miles? Wow.
Only thing I can think off the top is if you ride the clutch
or hold the clutch in for long periods i.e. at long stoplites,
or run higher rpm than is the norm during cruising a lot.
Holding the clutch in would increase tension on that throwout
bearing and therefore probly the heat it generates, having an
effect on the seals and causing them to leak a little. The red
color of the jelled fluid that leaked out shows excess heat.
I agree it could be a better design concept as that throwout
bearing is constantly under tension and spins constantly at
engine rpm. I thought my way thru that one awhile ago and
realized that that bearing spins constantly and under load from
the spring behind the piston in the slave. If that was not the
case, there would be wear where the clutch pushrod contacts
the diaphram spring if the pushrod didn't spin with the spring.
Seems with everything considered that the old cable release
system was simpler but more reliable, even tho it took some
occasional adjustment. Not to mention less costly to repair.
And the slave apparently requires replacement more often than
it should or places like Beemerboneyard wouldn't carry them.
But 4k miles? Wow.
Only thing I can think off the top is if you ride the clutch
or hold the clutch in for long periods i.e. at long stoplites,
or run higher rpm than is the norm during cruising a lot.
Holding the clutch in would increase tension on that throwout
bearing and therefore probly the heat it generates, having an
effect on the seals and causing them to leak a little. The red
color of the jelled fluid that leaked out shows excess heat.
I agree it could be a better design concept as that throwout
bearing is constantly under tension and spins constantly at
engine rpm. I thought my way thru that one awhile ago and
realized that that bearing spins constantly and under load from
the spring behind the piston in the slave. If that was not the
case, there would be wear where the clutch pushrod contacts
the diaphram spring if the pushrod didn't spin with the spring.
Seems with everything considered that the old cable release
system was simpler but more reliable, even tho it took some
occasional adjustment. Not to mention less costly to repair.
And the slave apparently requires replacement more often than
it should or places like Beemerboneyard wouldn't carry them.
Re: Clutch Slave Cylinder
I live in the land of stop signs and traffic lights and most of those 4000 miles were put on with a short commute to the the train with 6 lights and 4 stop signs in 4 miles or if I took the long way 10 signs and 12 lights within about 7 miles. So I could see that stressing the clutch a bit.
Re: Clutch Slave Cylinder
That does not look good 
What indication/symptoms did you have?
If it were mine, I'd replace that felt washer inside the tranny tube that is supposed to keep that kind of yak off the clutch disk...which I hope it did.
What indication/symptoms did you have?If it were mine, I'd replace that felt washer inside the tranny tube that is supposed to keep that kind of yak off the clutch disk...which I hope it did.
Rich
ADIOS!
ADIOS!
Re: Clutch Slave Cylinder
I'd say! That's probly 5 or more times the stops per mile than anegates wrote:I live in the land of stop signs and traffic lights and most of those 4000 miles were put on with a short commute to the the train with 6 lights and 4 stop signs in 4 miles or if I took the long way 10 signs and 12 lights within about 7 miles. So I could see that stressing the clutch a bit.
average rider has.
About the only thing you could do there is to shift into neutral as you
coast to a stop at a red light or stop sign, and let the clutch out until
it's time to go.
Re: Clutch Slave Cylinder
no symptoms at all really - never really had a problem with the clutch. the disk is in good shape.Sunbeemer wrote:That does not look good
If it were mine, I'd replace that felt washer inside the tranny tube that is supposed to keep that kind of yak off the clutch disk...which I hope it did.
I pulled the slave cylinder only because I needed to replace the clutch housing (flywheel) because it and the starter decided to chew each other up (that's a previous post).
I'll have to check on the felt washer.
This job of replacing the clutch housing and rebuilding the starter was hard enough, I really didn't need this added on top of it.
Thanks.
Re: Clutch Slave Cylinder
It is my understanding that the clutch slave is under tension from the moment it is installed.
The part wears out just sitting in your garage, not so much as a result of riding style or commute.
That little felt piece probably saved your clutch disc, agree with replacing it.
You should pump a bottle of Dot4 through the clutch circuit too, make sure none of that gunk is
left in the system.
The part wears out just sitting in your garage, not so much as a result of riding style or commute.
That little felt piece probably saved your clutch disc, agree with replacing it.
You should pump a bottle of Dot4 through the clutch circuit too, make sure none of that gunk is
left in the system.
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CycleRob
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Re: Clutch Slave Cylinder
egates,
The picture doesn't show a lot of fluid leakage. It shows a tiny leak whose liquid has dried out, leaving a jelly deposit behind. That kind of weepage could happen with an overheated engine and the stress of holding the clutch in at all those lights and stop signs. A tiny tenth of a drop/day would weep out, dry out and become the jelly deposits we see.
I would take the master cylinder apart to thoroughly clean it out, blow contact cleaner thru the lines then blast them out with shop air. You may want to take the slave apart too so the bearing, bore and piston seal can be closely examined for what caused the weeping. If you see the slave bore has been scored by the piston spinning, it most likely is a failed bearing in the slave piston and it must be replaced. If you see nothing wrong and the bearing spins smooth and quiet, it likely was the engine overheating that caused the minuscule weeping. I base this assessment on the slave's really short 4K mile service life. Since a new slave is ~$100 at a discount, it may pay to consider an undamaged cleaned up one as reusable, unless you really dread the slave R&R in a year.
.
The picture doesn't show a lot of fluid leakage. It shows a tiny leak whose liquid has dried out, leaving a jelly deposit behind. That kind of weepage could happen with an overheated engine and the stress of holding the clutch in at all those lights and stop signs. A tiny tenth of a drop/day would weep out, dry out and become the jelly deposits we see.
I would take the master cylinder apart to thoroughly clean it out, blow contact cleaner thru the lines then blast them out with shop air. You may want to take the slave apart too so the bearing, bore and piston seal can be closely examined for what caused the weeping. If you see the slave bore has been scored by the piston spinning, it most likely is a failed bearing in the slave piston and it must be replaced. If you see nothing wrong and the bearing spins smooth and quiet, it likely was the engine overheating that caused the minuscule weeping. I base this assessment on the slave's really short 4K mile service life. Since a new slave is ~$100 at a discount, it may pay to consider an undamaged cleaned up one as reusable, unless you really dread the slave R&R in a year.
.
`09 F800ST
Member since Sept 10, 2001
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iowabeakster
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Re: Clutch Slave Cylinder
Starter, flywheel, and clutch slave and only 4000 total miles on the bike? That does suck...
Is this a used bike? Do you know the service history of the clutch fluid?
It doesn't have the stainless brake lines... so it must be an 02 or an 03. Fluid should be changed every 2 years...
Is this a used bike? Do you know the service history of the clutch fluid?
It doesn't have the stainless brake lines... so it must be an 02 or an 03. Fluid should be changed every 2 years...
I was dreaming when I wrote this, forgive me if it goes astray...
Re: Clutch Slave Cylinder
Its mine since new and it was dealer serviced (by BMWNY and Precision on Long Island, NY - both out of business at this point and their service was horrible). I'd have to look through receipts but I know the clutch fluid was not replaced recently. I was not planning on replacing it now either because of the trouble I've read of bleeding the system but I guess I should just bite the bullet and since its all apart just do it already.iowabeakster wrote:Starter, flywheel, and clutch slave and only 4000 total miles on the bike? That does suck...
Is this a used bike? Do you know the service history of the clutch fluid?
It doesn't have the stainless brake lines... so it must be an 02 or an 03. Fluid should be changed every 2 years...
Re: Clutch Slave Cylinder
Yes, it can be "real fun"!
I went thru a lot of problems last spring after a clutch replacement.
Rec'd lots of helpful suggestions on this site, too many and too much
info to repeat here.
Just do a search on my posts about clutch bleeding.
Some folks have an easy time of it, but some like me don't.
Who knows why? You can save yourself some significant $
by DIY. Just like on brake bleeding.
Good luck!
I went thru a lot of problems last spring after a clutch replacement.
Rec'd lots of helpful suggestions on this site, too many and too much
info to repeat here.
Just do a search on my posts about clutch bleeding.
Some folks have an easy time of it, but some like me don't.
Who knows why? You can save yourself some significant $
by DIY. Just like on brake bleeding.
Good luck!