mine is leaking, whats the best way to mend it? is there a repair seal kit? cant find one . there are few units on ebay from later bikes - looks the same but not sure they will fit?> any ideas?
How early ? The clutch rod length changed and I can’t remember which year. I believe your’s should be the longer rod. Andy
here is my current slave cylinder . is it correct for the model? mine is 1995 Senna Mk1 916 ? most of the others ive seen looks different?
and rubber dust seal on the plunger behind the cylinder is perished . anyone knows part number for replacement one?
I bought a clutch slave seal kit for my 916 from Moto Rapido. Their service was excellent and they were careful to ensure I was sent the correct one for my model and year. Good luck. Cheers 2Twins
if you can get away with a new seal/bore not badly worn then it's the cheapest fix by far. Yours looks like the early 25 mm unit. If you want to try getting a slightly lighter effort at the lever you could try an aftermarket slave (i'm sure you knew that) or even a secondhand later Ducati unit. (749 is 27.5 or 28 mm which is a nice compromise) This is always a compromise as lever will travel further as a result and may not suit you Have done this many times as they can still turn up for £25-30 posted from breakers. As said, you need to determine pushrod length. You can check slaves back-to-back by measuring how far pushrod protrudes in slave with 'piston' pushed to bottom of bore travel.
i'm tempted myself:--) https://www.ebay.co.uk/itm/Ducati-7...981780?hash=item4b5514ec54:g:7JAAAOSwXc9b7Gcr £20 offer might be a winner.
But it looks different to the one I have on the bike now... or is this one a correct one for 95 senna 916?
Sorry, just read your reply properly... all clear now. Want to stick with originality! Will try to repair mine. Thanks a lot!
I am going to order all the bits and refresh my current unit . Do I need to replace piston? Or would that be ok? Piston is 44 fucking Euro!
have you stripped it yet? piston nearly always fine unless has rusted badly, it's more the bore in the cylinder body you need to study carefully for heavy scoring/wear. That said, wear has to be severe for a new seal to not work - although life possibly reduced.
the piston normally comes out fairly easily but if it's sticking for some reason you could leave the hose connected and carefully try and pump it out with the lever but it's possible you have little resistance at the lever as slave seal is leaking/failing. - lots of old rags needed to smother the whole cylinder when you do this. this is the only guide I found so far and haven't watched it all the way through:-
9 years ago when I was renovating my 916 I bought a s/h slave off a guy on the old forum for a couple of quid, it was siezed solid but I was able to pump the old piston out. Inside the cylinder was manky to say the least and the piston was not much better. About an hour's work with some old 1200 wet and dry with soapy water, the piston was clean and smooth and the bore of the cylinder was mirror finished. With a new seal (the later modified one) it worked perfectly and still does. A relatively quick easy and cheap job to do and worth doing.
Technical question...when the slave is installed, is there still a small amount of permanent pressure from the fluid, pushing the slave into the clutch rod even when you do not pull the lever back? I note many slaves now use grooved piston seals, which are only designed to seal in one direction. So to avoid the seal being breached the other way, surely they need a little bit of pressure at all times?
no, there shouldn't be any hydraulic pressure acting against the mechanical springs at the pressure plate normally but it can happen.
The master cylinder has a port which enables the fluid to move back into the reservoir to the point where there is no force on the pushrod. But your lever must be adjusted properly, i.e. have a few mm of play, for the port to be exposed. When you start pulling in the lever the port is sealed and the fluid acts on the piston.
