clutch problem
 

Hi All,
Just got back from the Nurburgring - what a place !! anyway, I had my first 'side stand moment' whilst there and the bike went down. Since it fell, I've had the clutch stop working on me twice, and hydraulic oil appeared on the floor. I've just replaced all the seals in and around the slave cylinder, that's fixed the leak, but I can't seem to get the thing to work again - it doesn't seem to want to pressurise the push rod at all. It appears to be fully bled, no air bubbles coming out of the bleed tube anyway, or up in to the master cylinder. Help ! I need the thing for monday !...

They are notorious for not bleeding very easily. You may have to try again???
Are you pumping fluid out, when bleeding, thru' pulling the clutch lever?? Damaged clutch master cylinder?
When you had the slave cylinder off, did you remove the pushrod? Is it moving OK?
Does the slave cylinder move at all whilst removed? If it does, then I'd reckon you've just got to bleed it until it works..........

Have you ever tried a Mity-Vac? These are amazing things, that allow you to vacuum-bleed any hydraulic system.

No lever-pumping necessary, and absolutely no possibility of air getting into the system. I used to really dread bleeding brakes/clutches, but now change my fluid after every race, just because its so easy.

I got mine at Hein Gericke - was about £35, if I recall, and worth every penny.

Friend of mine has just bought one of these from Heine Gerrick, and although it looks a tad "cheap" for £35 he swears by it, says it takes about 5-10 mins to bleed the system...

Yup, been using one myself for 2 years. Wouldn't do it any other way. Great for reverse bleeding, i.e. at the master cylinder.

Sorted. TOP TIP: Always bleed your clutch on it's side stand, NOT on a paddock stand !!
Doh !! I spent all day Sunday trying to fettle it, went and bought an Eezi-bleed kit yesterday (crap without the right cap - oil everywhere) then just thought I'd 'try it' on it's side stand. Hey presto, done and dusted in 10 minutes. Oooh Bugger.

I am not sure you can conclude that it has be done on the sidestand. Probably just concidence.

Air bubbles rise to the highest point in a hydraulic system so that's where bleed nipples belong and are usually placed. In Ducati superbikes the bleed nipple is placed at the lowest point in the system (duh) so the only way you can bleed all the air out is for the bubbles to be carried along with the fluid as you bleed, and bleed, and bleed the system. It is possible to bleed the system without using a bleed nipple at the master cylinder, but it takes a lot more work.

So, the Ducati clutch line is notoriously difficult to bleed using just the nipple at the clutch slave cylinder. Evoluzione and Yoyodyne, two aftermarket manufacturers of slave cylinders, encountered customer bleeding problem complaints so begin selling a banjo fitting having a bleed nipple for use at the highest point in the hydraulic system. It works.



However, you don't necessarily need one. You can try just loosening the bolt slightly and bleed with the regular banjo bolt as if it were a bleeder type. Careful though, any sprayed hydraulic fluid will damage painted surfaces.

You could also remove the master cylinder from the handlebar, and position it so the banjo fitting is down and the reservoir is above it.

Darryl Samson posted a clever idea recently. Use a large balloon, inflated and fitted over the top of the reservoir as a pressure bleeding system. Just blow it up and put a tie around it so you can stretch the mouth of it over the top of the reservoir (after filling it) and release the tie.

One workable approach is to have one person pump the clutch lever like hell (then hold it in till the bleed nipple is opened and closed again), another person keeps the clutch master cylinder fluid level full, and a third person opening and closing the slave cylinder bleed nipple while watching for bubbles. Remember the flow has to carry the bubbles down and out. Eventually the pressure builds, lever firms up and the bubbles stop. Go for a ride and then bleed it again to be sure.