Clutch hydraulics problem

[Lost_Coast_Paso]

Recently the clutch began to fail to stay disengaged for more than a few seconds. The Ducati dealer told me that the seal on the slave cylinder was prone to failure, so I ordered new seals for it. I have installed the seals but I'm unable to bleed the system. Very little pressure develops when I pump the clutch lever, and very little fluid is leaving the master cylinder. Maybe the seals in the master cylinder are are worn out and caused the original problem. Maybe this system is just difficult to bleed using the conventional method. What do you think? Thanks.

[ducbertus]

hi,

The symptoms you're discribing is your lose somewhere some fluid.
I think that you already mentioned the most likely cause of leaky seal in the master cylinder. You can buy a repair kit and replace the complete piston, seal and spring.
when you assembling the parts aply a coat of break grease.

if the line is difficult to bleed, just take the mastercilinder from the handlebar and tie up the mastercylinder in such a way that the reservoir is the highest point.
The trapped ait tends to rais to the highest point.
if you operate the clutch lever several times, you must be able to get all the air out of the line.
furthermore check the adjusting screw in the handle bar. this should not screwed in to far.
otherwise the piston blocks the hole which is the connection between the reservoir and the area in front of the piston of the mastercylinder.

goodluck, Ducbertus

[jcslocum]

Sounds like you have an air bubble at the banjo fitting where the hose to the clutch connects to the master cylinder. So little fluid is pumped each stoke that this bubble can be VERY hard to eliminate. Use a good vacuum bleeder.

One trick is to turn the bars full right, tie wrap the clutch lever all the way in to the grip and levae it overnight. This allows the air bubble to migrate up to the reservior.

Good luck!!!

[kirk332]

I am certainly no expert here as I too am having some clutch issues, however I think they are more to do with clutch plate setup. I was able to bleed my system, I think relatively effectively and easily, by using a meter of clear plastic hose attached to the bleed nipple (make sure it's a tight fit), only lightly crack the nipple open and then suck on the open end of the hose, making sure that you standing up and that the hose is vertical. Make sure the cover is off the reservoir so that you can keep topping it up while sucking on the hose. (Clutch lever to be fully out i.e., hands off) It didn't appear to be getting any air coming in from the threads of the bleed nipple, which you would assume would happen. If you do suspect that this could/is happening you could try putting some Vaseline around the threads and also apply a bead around where the threads come out of the housing to help seal the area. (Understand??)

[DesmoDog]

Before you do anything else, try this. Turn the bars to the right, now lean the bike over until the master cylinder is the highest point in the system. Now slowly pump the lever a few times.

I'll bet you have pressure now...

Without doing this it was impossible for me to bleed the clutch or brake on my 907. When I did this is was quite easy to bleed it. You don't even need to open any bleeder screws, just lean the bike and SLOWLY pump the lever a few times. BE CAREFUL if you are doing this with the cap off! At first the m/c will pump air bubbles out, but then it will shoot a stream of fluid up and out. Some m/c have a little internal cover to prevent this, others don't.

It'll work, trust me!

On my 900ss I even deleted the clutch's bleed screw (not by choice, it was an emergency repair) and bled the clutch using this method. It's often a very simple problem when you look at it - when in place the master cylinder is too low to bleed properly and it will basically bleed itself if given the chance.

[Lost_Coast_Paso]

Thanks very much for all the info.

I decided to replace the seals in the master cylinder because I don't know how old they are. The Ducati dealer said that Ducati and/or Brembo does not make the seal kits any more. LT Snyder referred me to yoyodyne, but I can't tell which, if any, of their seal kits will fit the 907. I think this kit may be correct:

http://www.yoyodyneti.com/ProductInfo.a ... 10.4362.91

Can anyone confirm this?

Thanks.

[persempre907]

I guess it isn't correct.
If I'm well recalling the clutch master cylinder is 13mm. and not 15mm.
But, I have to check it.
Ciao

[Lost_Coast_Paso]

I guess it isn't correct.
If I'm well recalling the clutch master cylinder is 13mm. and not 15mm.
But, I have to check it.
Ciao

You're right. I did more reading at Yoyodyne. I believe this is the correct kit for 13mm master cylinders: http://www.yoyodyneti.com/ProductInfo.a ... 10.4362.50

Thanks.

[eliatt]

Hi,
Take a look at this:
http://www.shop.bevelheaven.com/detail.aspx?ID=395

[persempre907]

You're right. I did more reading at Yoyodyne. I believe this is the correct kit for 13mm master cylinders: http://www.yoyodyneti.com/ProductInfo.a ... 10.4362.50

Hi,
Take a look at this:
http://www.shop.bevelheaven.com/detail.aspx?ID=395

Really, it's the same item...
This is the good one.

Ciao

[Lost_Coast_Paso]

Hi,
Take a look at this:
http://www.shop.bevelheaven.com/detail.aspx?ID=395

Really, it's the same item...

Ciao[/quote]

Yes, it seems the same, but I am glad to learn of another place to buy parts.

Thanks.

[beemerboy]

Wow, I've been experiencing some clutch problems the past few weeks and decided to log on and use the search function then found this timely post. I have no fluid showing in my master cyclinder's sight lens which may be an indication of a system leak, I'll be pulling the plastic this week to inspect the slave cyclinder. What puzzles me is that I have less than 4K miles on a brand the new Brembo assembly I installed in 2005. Are the components so sensitive that they require regular replacement??

[ducbertus]

no,

normally these parts should last much longer. My expirience is that they do.
may be just bad luck this time.
When you assemble them properly and use the right kind of grease, you should face no problem.

Ducbertus

[ducatipete]

For bleeding of hydraulics systems I recommend using a Mity Vac, a US product like a hand held pistol, that draws the fluid thro the bleed screw, using vaccuum pressure, you just need to top up the fliud in the reservoir,,,it uses clear plastic tubes so you can see the air bubbles coming out....very quick and easy,,,,has many uses for bikes and cars,,,,,