Signs of a leaking clutch slave? (Yoyodyne)

[erkishhorde]

The last time my clutch slave went out on me I think it was rather sudden. I was scooting around surface streets and the clutch pull started feeling funny loose. Then after that it suddenly lost all resistance and the bike died while stopped at a light.

Recently I have been noticing that the clutch pull isn't going all the way and is stiff at times. I can usually pull all the way to the bar but all of yesterday clutch pull felt a bit stiff and I couldn't pull all the way to the bar. The bike would also pull a lot in first w/ the clutch pulled in. In the previous week it's been on and off but it was happening all day yesterday. Now, when I went out to the bike to try today, it pulls just fine.

I recently had the clutch hub nut come loose but I tightened that up and that is not the problem this time. I pulled the clutch plates and saw nothing glaringly wrong. I pulled the slave (Yoyodyne) and noticed some black liquid dribble out of the clutch slave. Wiped it up and a few minutes later a little more dribbled out. The consistency is very watery but has a bit of a film to it. I'm thinking it might be leaking brake fluid. I recently (when the clutch hub nut came loose ~2 weeks ago) replaced the little O-ring that goes around the push rod between the engine case and the slave. I vaguely remember black liquid dribbling out of the clutch slave then too but didn't think anything about it.

Think this is a sign of a leaking slave? If not, what else do you think it is?

edit: got around to dismantling and trouble shooting. This is what I found:

The was rust around the 2 holes at the bottom the master cylinder as well as a bunch of sludge stuck in the valleys along the 2 long sides of the coffin. I emptied out the coffin and cleaned that up. Hopefully it should last me a bit longer and then I'll upgrade later.

As for the Yoyodyne, I popped it open and it spit out strips of silicon I'm not sure what it was but it came from between the piston and the outer plate. Also the outermost O-ring on the piston (big one on the left) was very distended and there was a bit of black goop mixed up lubricant that I found in the slave housing. I couldn't get my pill out to examine it but it doesn't look too bad. Did I mention that there were gold flakes in the dirty brake fluid that was leaking out of the slave?

off the bike (view image to see bigger)


outa the box


Hopefully all I have left to do is get Yoyodyne to replace it under warranty. Hope that's not too much trouble.

Conclusion:
So to wrap things up:

Yoyodyne received my clutch slave and is sending me replacement bits under warranty.  I really lucked out in that the older monsters need an extender pill between the pushrod and the piston. The pushrod destroyed this and saved me from drilling a hole through the piston w/ my push rod. On top of that they suspect that the O-ring around the pushrod between the slave and the engine broke and let oil into the slave which contributed to the failure of the O-rings on the slave. I can verify this by the fact that the O-ring in question was totally destroyed when I last popped the slave off a couple months ago when my clutch hub nut came loose and I had taken everything apart to inspect.

So, if all goes well I'll get my return bits by Friday and can put the bike back together this weekend. Then it's  time! I've missed riding so much these last 2 weeks. 

[Ddan]

A leaky slave would be more likely to give a soft lever.  What you're describing sound more like a problem with the return bleed in the master.  Have you made any adjustments recently?

[Capo]

Any leak would cause the level in the reservoir to fall.  Have you had to top it up?

[erkishhorde]

I popped the top of the reservoir and it didn't look low. I haven't tweaked anything either. Any ideas what the black liquid is coming out of the slave? Is it something I should be worried about?

[Capo]

Well if it is leaking, there is a lifetime warranty.

There is a small vent hole on the back, is this where the 'black' fluid is comming from?

[erkishhorde]

The black liquid is dribbles out a couple drops at a time from where the piston goes in. It's also got gold flakes in (the little pill in there is gold so I figured it was coming from that).

[Capo]

Take your pressure plate off and check that the bearing is in good condition.

[erkishhorde]

Opened it up tonight and added results to the OP.

The last time my clutch slave went out on me I think it was rather sudden. I was scooting around surface streets and the clutch pull started feeling funny loose. Then after that it suddenly lost all resistance and the bike died while stopped at a light.

Recently I have been noticing that the clutch pull isn't going all the way and is stiff at times. I can usually pull all the way to the bar but all of yesterday clutch pull felt a bit stiff and I couldn't pull all the way to the bar. The bike would also pull a lot in first w/ the clutch pulled in. In the previous week it's been on and off but it was happening all day yesterday. Now, when I went out to the bike to try today, it pulls just fine.

I recently had the clutch hub nut come loose but I tightened that up and that is not the problem this time. I pulled the clutch plates and saw nothing glaringly wrong. I pulled the slave (Yoyodyne) and noticed some black liquid dribble out of the clutch slave. Wiped it up and a few minutes later a little more dribbled out. The consistency is very watery but has a bit of a film to it. I'm thinking it might be leaking brake fluid. I recently (when the clutch hub nut came loose ~2 weeks ago) replaced the little O-ring that goes around the push rod between the engine case and the slave. I vaguely remember black liquid dribbling out of the clutch slave then too but didn't think anything about it.

Think this is a sign of a leaking slave? If not, what else do you think it is?

edit: got around to dismantling and trouble shooting. This is what I found:

The was rust around the 2 holes at the bottom the master cylinder as well as a bunch of sludge stuck in the valleys along the 2 long sides of the coffin. I emptied out the coffin and cleaned that up. Hopefully it should last me a bit longer and then I'll upgrade later.

As for the Yoyodyne, I popped it open and it spit out strips of silicon I'm not sure what it was but it came from between the piston and the outer plate. Also the outermost O-ring on the piston (big one on the left) was very distended and there was a bit of black goop mixed up lubricant that I found in the slave housing. I couldn't get my pill out to examine it but it doesn't look too bad. Did I mention that there were gold flakes in the dirty brake fluid that was leaking out of the slave?

off the bike (view image to see bigger)


outa the box


Hopefully all I have left to do is get Yoyodyne to replace it under warranty. Hope that's not too much trouble.

My dad said something about my forgetting to but some grease on the OTHER (pressure plate) side of the push rod could have contributed. Perhaps the rod was making too much contact w/ the pressure plate and the spinning of the rod contributed to the death of my slave. Opinions?

[erkishhorde]

So to wrap things up:

Yoyodyne received my clutch slave and is sending me replacement bits under warranty.  I really lucked out in that the older monsters need an extender pill between the pushrod and the piston. The pushrod destroyed this and saved me from drilling a hole through the piston w/ my push rod. On top of that they suspect that the O-ring around the pushrod between the slave and the engine broke and let oil into the slave which contributed to the failure of the O-rings on the slave. I can verify this by the fact that the O-ring in question was totally destroyed when I last popped the slave off a couple months ago when my clutch hub nut came loose and I had taken everything apart to inspect.

So, if all goes well I'll get my return bits by Friday and can put the bike back together this weekend. Then it's  time! I've missed riding so much these last 2 weeks. 

[Capo]

The rod should be a slight interference fit in the pressure plate bearing, the rod stays still and the plate rotates around it no grease required.
You should inspect the rod for any damage, and for sure replace the O ring that is located on it.

[erkishhorde]

Yeah, i think the pressure plate bearing is frozen. I've been meaning to look at it but never got around to it. 

[Howie]

You need to check it before installing the slave.  Actually, you might as well replace it as preventative maintenance.  Chris Kelley has inexpensive quality replacements. 
http://www.ca-cycleworks.com/shop/catalog/ducati/engine.html
Scroll down

[erkishhorde]

You need to check it before installing the slave.  Actually, you might as well replace it as preventative maintenance.  Chris Kelley has inexpensive quality replacements. 
http://www.ca-cycleworks.com/shop/catalog/ducati/engine.html
Scroll down

Hmmm... I'm thinking "it" refers the to the thing the push rod sits in on the pressure plate but I don't see much of anything on the site in reference to that. Am I missing something? What's it called exactly? i know what it should look like and where it is but I can't see anything that looks like it might be the right thing unless I just get a whole new pressure plate. A new pressure plate is the whole thing, right? As in the bearing isn't supposed to re-used from the stocker?

[Howie]

Hmmm... I'm thinking "it" refers the to the thing the push rod sits in on the pressure plate but I don't see much of anything on the site in reference to that. Am I missing something? What's it called exactly? i know what it should look like and where it is but I can't see anything that looks like it might be the right thing unless I just get a whole new pressure plate. A new pressure plate is the whole thing, right? As in the bearing isn't supposed to re-used from the stocker?

Clutch throwout bearing Ducati 6 speed All dry clutch 6201 $9.00  add to cart 

Usually a new pressure plate comes with the bearing.  The bearings themselves are replaceable as a part.  With a suitable driver (a socket or piece of pipe that contacts the outer race, but is smaller than the boss in the pressure plate will do), knock the old one out.  Tap the new one in, job done.  Note the orientation of the pressure plate and reinstall in the same position.  There will be a mark on the pressure plate and the basket, or you could make your own.

[erkishhorde]

Oh, someone suggested replacing the throwout bearing already and I got it already. Just hadn't opening my manual to see where it went.  I kinda thought it might go there. I had the part shipped home and my dad called me up wondering where it went and telling me I was wasting money since he couldn't figure out where to put it either.