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Discussion Starter #1
I installed a 14-tooth countersprocket on my 2013 M796 yesterday, and had to remove the clutch slave cylinder in order to do so. After reinstalling everything, and starting the bike and putting it in first gear, the drive train did not engage at all. So, I removed the slave cylinder to have a look at the sprocket and see what could have gone wrong. Everything looked fine, so I attempted to reinstall the slave cylinder, but could not get it to reseat properly again. It's as though the push rod is not fully seating, causing the slave to stick out, but I don't understand how that rod could have been moved at all from simply removing the slave cyclinder. The push rod easily comes out completely, and is clean and lubricated, and appears to seat properly when reinstalled, but it must be not fully seated?

Attached is a pic showing how the slave cylinder will not seat against the engine case, and one of the push rod (showing how far the pins on the rod are from the engine case, as the rod will not seat more than this).

Any ideas?

Thanks.
225029


225030
 

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I'm guessing that you do have the pin lined up with the slot. Did the clutch lever accidentally get pulled while I was off? May just need to use a little force to push the piston back to it's resting position.
 

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Thanks for the response. I figured it out: the piston inside the slave cylinder was expanded, thus not allowing the push rod to seat properly within the cylinder. (And yes, stupidly, I had pumped the clutch lever while the slave cylinder was removed from the bike.) Once I removed the bleed screw and pumped the lever (squirting fluid from the cylinder), the piston relaxed and I was able to reinstall the slave cylinder. Now I just need to properly bleed the line and hopefully I'll be back in business.
 

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I'm guessing that you do have the pin lined up with the slot. Did the clutch lever accidentally get pulled while I was off? May just need to use a little force to push the piston back to it's resting position.
Now that I've got it all back together, the clutch adjustment screw at the lever had to be screwed all the way in to get the clutch to engage, and even with this adjustment there is some motion of the rear wheel when I pull the clutch and drop it into first gear (on rear stand).

Any thoughts re: why I would have to make this much adjustment? I did a bleed and topped up the reservoir.

Thanks,

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Probably needs more bleeding. They can be a pain to bleed at times simply because it doesn't create as much pressure as something like the brakes. And it can vary based on the angle of the master cylinder and banjo connection. Sometimes it helps to put the cap back on the master and remove the lever from the handlebars and raise it up and hold it in a few different positions for a few seconds at a time to help get any trapped air out. It still needs to remain fairly level or you might get even more air in there.

In the future, you do not need to loosen the bleeder to push the piston back in. As long as the lever is released, it will simply push the fluid back into the reservoir. Just like with brakes. You will feel some resistance, but it will move. Whenever I have the calipers or clutch slave off for more than a few minutes, many times I just pop the levers off completely. Just to avoid that type of situation.

You may want to consider investing in something like a Mity-Vac or something similar. It can really speed things up on systems like the clutch and rear brake when you have a lot of trapped air and not much pressure to work with. Once you get the bulk of it out, finish it off the old fashioned way.

Yes, DOT 4, or 3-4.
 

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Discussion Starter #8
Probably needs more bleeding. They can be a pain to bleed at times simply because it doesn't create as much pressure as something like the brakes. And it can vary based on the angle of the master cylinder and banjo connection. Sometimes it helps to put the cap back on the master and remove the lever from the handlebars and raise it up and hold it in a few different positions for a few seconds at a time to help get any trapped air out. It still needs to remain fairly level or you might get even more air in there.

In the future, you do not need to loosen the bleeder to push the piston back in. As long as the lever is released, it will simply push the fluid back into the reservoir. Just like with brakes. You will feel some resistance, but it will move. Whenever I have the calipers or clutch slave off for more than a few minutes, many times I just pop the levers off completely. Just to avoid that type of situation.

You may want to consider investing in something like a Mity-Vac or something similar. It can really speed things up on systems like the clutch and rear brake when you have a lot of trapped air and not much pressure to work with. Once you get the bulk of it out, finish it off the old fashioned way.

Yes, DOT 4, or 3-4.
I got the Mityvac today and tried to bleed the clutch, but no matter what I do, almost no fluid comes out. The Mityvac appears to be pressurizing properly, but when I crack the bleed screw on the slave cylinder nothing comes out other than a very few drops. Any thoughts? I thought the Mityvac was supposed to provide enough pressure to overcome the low pressure of the clutch system?
 

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Ok. So the cap is off the master cylinder and it's topped off. You have the pump and fluid cup all set up. When the tubing is on the nipple of the bleeder with it fully closed, you can build up around 20 in. of vacuum and it holds it pretty well? You may see it slowly creeping down but that is normal. When you crack the bleeder what happens with the vacuum gauge? If it's mostly air coming out of the system you should only be able to open the bleeder for a second or two before losing most of your vacuum. Even while pumping it as you go. If you're not getting fluid out, that gauge needle should be dropping like a rock every time you crack the bleeder open. And you should see the fluid level gradually going down even if you're not seeing it on the other end yet. If it's not, something is wrong. I've never torn one of those factory slave cylinders apart, so I'm not sure if it's physically possible to push the piston too far back or not. You mentioned earlier tightening the adjustment screw on the lever. Is it possible that it could be actually moving the cylinder forward?
 

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Discussion Starter #10
I got the Mityvac today and tried to bleed the clutch, but no matter what I do, almost no fluid comes out. The Mityvac appears to be pressurizing properly, but when I crack the bleed screw on the slave cylinder nothing comes out other than a very few drops. Any thoughts? I thought the Mityvac was supposed to provide enough pressure to overcome the low pressure of the clutch system?
I got it to bleed by backing the adjustment screw on the master cylinder all the way out. I think I've got all the air out now, but the clutch adjustment screw on the master has to be screwed almost entirely in before the clutch will stop the rear wheel from spinning in gear while on a rear stand. I know many of the clutches on Ducs I have had over the years do this - the rear wheel will spin a bit while in gear on a rear stand while the clutch lever is pulled - but I would think I should be able to adjust this out via the adjustment screw, so that the clutch engages before the lever is pulled virtually all the way in. ??
 

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Well that's good you got it to flush. One vacuum working against another doesn't get very far. Striving for that full disengagement of the clutch has always been a thing with me too. And the adjustment screw only seems to throw off the feel of the clutch. It's pretty much a wet clutch thing in general. And Ducatis tend to have more plates and a shorter engagement than many other bikes. That's way I moved away from Motul. It's good oil, very sticky and the motor loves it. But I don't care for how it drags the clutch.
 

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Discussion Starter #12
I think our messages crossed. Yes, your description is what I get with the Mityvac: I pump it up to about 20, and it does slowly lose pressure. So, I crack the bleed screw quickly and the Mityvac immediately drops to no pressure. So, it seems that is working properly.

I think the key was backing out the adjustment screw at the master cylinder. Once I did that, the fluid came out pretty strong for an initial burst whenever I cracked the screw. So, I did that a few times.

I may end up removing the lever completely and bleeding it again, to see if I can get more range out of that adjustment screw. For now, it works, albeit with the lever pulled to about 3/4 before any engagement.

Thanks for all of your help. I appreciate it.
 

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Hey man

I had the same problem.

The problem is that when u try to bleed the clutch with compressing the clutch lever it dose not apply enough pressure on the clutch master cylinder piston.

In other words,when you are compressing the clutch lever the piston is not travelling far enough in to the master cylinder to create enough pressure on the clutch line in order to be blead properly.

What i did on my bike is,
1. Remove the clutch lever off the master cylinder.
2. Remove the master cylinder piston pin
3 Place a philips screwdriver carefully on the clutch master cylinder piston and compress it (just like how you would compress it with the lever)
4. Make sure you are compressing the piston fully ( will take some effort)
5 You will notice that the resistance of the piston is increasing (pressure building up on the clutch line)
6 Continue the process until satisfactory results achieved.
 

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Discussion Starter #14
Hey man

I had the same problem.

The problem is that when u try to bleed the clutch with compressing the clutch lever it dose not apply enough pressure on the clutch master cylinder piston.

In other words,when you are compressing the clutch lever the piston is not travelling far enough in to the master cylinder to create enough pressure on the clutch line in order to be blead properly.

What i did on my bike is,
1. Remove the clutch lever off the master cylinder.
2. Remove the master cylinder piston pin
3 Place a philips screwdriver carefully on the clutch master cylinder piston and compress it (just like how you would compress it with the lever)
4. Make sure you are compressing the piston fully ( will take some effort)
5 You will notice that the resistance of the piston is increasing (pressure building up on the clutch line)
6 Continue the process until satisfactory results achieved.
Thanks. I'll try this if I find the clutch needs further adjustment.
 
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