Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 998 / 996 / 916 / 748 > Clutch Presure Problem (Update)

[Mr C]

I have a really anoying problem on my 996 at the moment with Losing Clutch presure. I recenty fitted a JHP oversized slave cylinder, bled it up no probs etc but avfter about 20 miles of riding i lose presure and have no clutch.
It is losing no fluid from anywhere and can be bled up again straight away but soon loses it again, This time within a shorter distance.
Just to iliminate it its not a push rod problem.
So any ideas?

This is part of the reason i replaced the Slave Cylinder:
http://217.199.188.40/xmb/viewthread...4456#pid124898

[Edited on 13-1-2005 by Mr C]

[Edited on 15-1-2005 by Mr C]

[andyb]

It would appear. if we assume that the new slave is A1, that there is an internal leak on the Master cylinder.

[GsxrAge]

I agree with andy b I had similar problem on my old 916 it needed new seals in slave cylinder. But yours is new but it still could be leaking

[Mr C]

One would presume that if Air is getting in then fluid is getting out, but I have no signs of fluid leaking from either cylinder.

[phil_h]

I assume you used all the other existing gear ... so the leak could be in the banjos, the lines, or the master cylinder !
Remember that the seals on the piston will not want to move by themselves (especially not if they are new and nice and tight), so as you release the lever, there is suction on the _whole_ system, not just the seals.
Sorry, sounds to me as if you replaced the wrong bit.

[chris.p]

I would tend to agree with andyb, it may sound strange but i have had 2 cases of this on my company car, both times the master cylinder was replaced, reason quoted was that when the clutch was used the piston in the master cylinder would travel to the back of the cylinder & force fluid back past the piston seal. Like I said sounds strange but it does sound similar?


Chris

[DAVE HARRIS]

I had this problem before and it turned out to be the release bearing in the clutch pressure plate, being a tight bar steward I removed the pressure plate and lubricated the bearing with wd 40 untill it was free and then sprayed some grease onto the bearing. the repair has lasted for 3 years!

It is fairly easy to spot if this is the fault if you remove the clutch cover you cab see the centre of the bearing in the centre of the clutch pressure plate
it should not spin with the clutch if it does try lubricating the bearing first before changing parts!! also it is common for the pushrods to snap and this can cause all kinds of clutch releadse faults

dave

[simonducati]

Dave is right I had the same problem but I found out the hard way, the push rod could be spinning and damaging your slave cylinder , this will course your fluid to go black in the master cylinder to because of the o-ring rubbing in the slave cylinder.

[FiscusFish]

Bleed it again and again and again... I'd bet you have air trapped up at the master cylinder banjo.

I'm also pretty sure the clutch fluid going black is a known Ducati problem as opposed to a simply the push rod spinning. My fluid used to go black with the standard cylinder and it still goes black with an Evoluzione slave cylinder on there (and that has an extra bearing inside it to stop the pushrod spinning if the release bearing fails)....

Darren

[Albie]

I would say its air. I had it on my monster. No leaks as new cylinders. Cost a packet for just air trapped. Tilt the bike over when bleeding as far as possible when sitting on it to the right. All the air will come out I assure you. All fluid goes black it seems. Maybe due to heat building up through push rod I dont know.Guess.