Hi everybody - it has been a while since my last visit, I am afraid to report, as my 1198s has been waiting, patently, in my garage whilst other, (equallly important issues), have taken precedence! When I did, eventually, find time to give her a shake down ride the clutch gave up the ghost approximately one mile from home and as I slowed for the local traffic lights I couldn't select neutral and the clutch was dragging very badly. The engine stalled so I then pumped the clutch lever and managed to select second and pull away without stalling the engine and I made it home without stopping! Upon inspection of the clutch assembly it would appear that the lever movement is resulting in an immediate and consistant movement of the 'pressure plate', (one of the benefits of an 'open' dry clutch is that you can see what is going on), but the clutch springs do not start to get compressed until the clutch lever is at two thirds of its travel! It is almost as if there is about 5mm of play in the clutch assembly and it takes 2/3 of lever travel to take up the slack! The clutch plates only really seperate when the clutch lever has reached the bar, (which is far from ideal), but there is definitely movement at the slave cylinder in sympathy with the full movement of the lever. I have bled the master cylinder, twice, and I have bled the slave cylinder, twice, and I have also stripped and cleaned the slave cylinder, (Oberon - not sure if this is a standard fitment or whether somebody has replaced the original), and there was no sign of leakage and all the seals look to be in good order. I decided to try and 'pre load' the slave cylinder by undoing the three mounting bolts, (by about 5mm), and I then pumped the lever to foce the slave cylinder piston outwards. I then tightened up the bolts so that the piston pushed the drive rod approximately 5mm from its neutral position, (taking up this 'slack), and the lever felt just like it used to - far more pressure/resistance than before and the clutch springs now began to compress as soon as I started to squeeze the lever. But as I squeezed the lever i then heard a distinctive 'buzzing' sound coming from the master cylinder which I am assuming is hydraulic fluid, (not air), forcing its way past the inner seals? If this is the case I am presuming that the 'play' in my clutch is probably quite normal and that the problem lies with my master cylinder? I repeated this 'buzzing' once more by repeating my 'pre load' experiment so it was not a one off! I have searched the forum for other reports of clutch problems but I have not found any quite like mine, (sincere apologies if I have missed it however), so I just wanted to know if anybody has experienced something similar and whether other, (far more experienced owners), would agree with my conclusion? I am planning to purchase a Brembo master cylinder seal kit but was surprised to note how expensive they are, (£39 from Ebay), so I would welcome any advice re any suppliers who can provide a seal kit for a few pennies less? I have maintained my previous dry clutches without any problems whatsoever, (916 and 999R), and I have never had any previous issues with a lack of efficiency! Thanking you all in advance - take care y'all and stay safe.
Sounds like you’re on the right track by diagnosing the clutch master as the source. Can’t advise on prices of rebuild kits though. GL.
If the lever is immediately moving the pressure plate, that would suggest to me that the hydraulics are ok and the problem is mechanical. Have you undone the bolts and taken the plates out? Have you looked at the pushrod and the release bearing? Does your set up require the extra extension for the pushrod? Have you checked the basket is on tight? Have you done anything to the clutch recently??
If you know which KTM uses the same master cylinder, they might do it a couple of quid cheaper. Is the eBay supplier you looked at Moto Rapido ? If it is at least you’ll know the kit is the right one. As to your issue, it certainly sounds hydraulic and my £1 would be the master cylinder. I had one do exactly the same which cost £100 to get rebuilt by Brembo. Andy
Come to think of it, If the hydraulics have air in there, pulling the lever could initially move the pressure plate but when extra pressure is applied as the initial play is taken up, the air starts to get compressed, so does nothing until it then eventually starts to move the springs when the air bubbles are sufficiently compressed. So yes, probably hydraulics.
Reason I ask is if you have a non-slipper, it is important that the little triangle on the pressure plate is aligned to the spring post with a notch in it. If one doesn’t do this, the teeth on the inside of the pressure plate will not engage with the teeth on the hub/drum. Result - clutch will not disengage fully. I know this as it happened to me many years ago.
Many thanks for your response. My first thoughts were that it was mechanical - too much slack - but everything is tight but there us approximately 4-5mm of 'play' or 'end float' with the assembly - but the infamous mounting nut is nice and tight 200ft/ib torque i believe from memory? The push rod is fine - as is the bearing - the exact same design as on my 916 and 999R! I have removed the plates and they are NOT original as far as I can tell and nothing like the varied mixture of plates as described in the service manual? I did look for the special mark on one of the clutch mounting columns and the reciprocal mark on the pressure plate but I can't recall seeing either! It is a standard clutch and not a slipper - as on my Tornado Tres - but it has the red Ducati Performance pressure plate. You mention an extension piece and whether I have undertaken any work on the clutch recently? I stripped the clutch before Christmas as it was jerking - the usual thing with these - and I just cleaned each plate and blew out the dust with my airline. I am intrigued re your mention of an extension piece however and I am now wondering whether it may have dropped out whilst I cleaned the plates last year - although not quite sure why it has only just started playing up now as it had covered a few miles since I stripped the clutch? Hopefully I was not that careless - but then again!
Andy many thanks for your response. Not sure what other bikes use this specific Brembo part unfortunately but I do have a couple of new non Brembo master cylinders so I could try one of those first and if it improves the situation I won't begrudge the money as it is Brembo after all! But would rather save myself time and money, (and embarrassment), if it's mechanical!!!
Many thanks for your replies to date - my next step will be to try a different master cylinder - just to prove/disprove my current theory! I always seem to get the 'esoterical' problems which appear very simple and straightforward - but are usually anything but! On a lighter note I have fitted a VERY cheap tracker to the 1198s, (about £20 from memory - with a 'pay as you go' SIM), which appears to work very well and I will post details about that ASAP as I am sure that may be of interest to some of the members.
When you get a new slave cylinder, it comes with a pushrod plus a small extension piece which you would or would not need according to the age of your bike and the design of the oem slave. Darned if I can remember which is which though. I’m now inclined to think the problem could be hydraulic and the initial movement isn’t compressing the air bubbles and then the next part of the movement compresses the bubbles with the final part of the movement actually compressing the springs themselves. The marks are a slot on top of one of the spring posts and a triangular arrow on the pressure plate
I’d bleed the clutch at the top nipple. Check the lever is connected properly. If still not works, and you have one, try another mc. if still doesn’t work then look to slave and clutch.
OR & Bradders, Many thanks once again for your further comments. I have bled the system twice and I am certain there's no air in the system although I have heard the odd story about slave cylinders needing to be turned upside down to ensure air can escape via bleed nipple! I did look for ident marks on the pressure plate, (not standard as it is the red 'Ducati Performance' part), but there is nothing visible and I can't recall seeing the ground mark on one of the stud mounting columns either? I know exactly what you are referring to as they were present on my previous Ducati's and I soon noted that the pressure plate would not sit correctly when not aligned correctly. I am still intrigued at the extension bar theory and could be tempted to find a suitably sized bolt and just placed it between slave cylinder and the push rod just out of interest!! I will take one more look before I can find a little time to remove the mc and substitute it with one oc my brand new, (non Brembo), items and see if the efficiency is improved - hopefully mid week - possibly Wednesday.
Not gone through all the thread.. Did you bleed with the lever span extended? Cracking the banjo, at the master can let trapped air escape, when the lever Is pulled. That's if no bleed nipple is fitted at the master.
The aftermarket extra piston to make up for a shorter actuation rod is from a much earlier bike than yours. Andy
FE, Yes I max'd out the span before pumping the lever before bleeding and I am fortunate in having a bleed nipple at the MC as well! Hopefully I have shifted any air and if I can swap the MC that may well prove whether it is the MC at fault. I will post a couple of pics and a video of my clutch 'action' later - in case anybody is interested! Despite working on many of these if you haven't got a good one to compare against your memory starts to play tricks on you!!
Andy, Many thanks for the update - you have saved me a trip to my garage as I was about to grind the head off a suitably sized bolt - just to test the theory!!
Here is a video clip of my clutch in 'action' note how the whole assembly moves outwards approximately 5mm before the clutch springs start to compress. It is only after the first 5mm of travel that the clutch plates begin to disengage with one another by which time the clutch lever is touching the bar! https://www.dropbox.com/s/ekdxffoqxia78pp/20200425_141501.mp4?dl=0 Here is a picture of the Clutch Slave Cylinder - but not sure if is standard fitment or a later addition? https://www.dropbox.com/s/9zxsgwl6pm8jxyu/20200425_141545.jpg?dl=0
When the clutch lever is fully in, can you turn the pressure plate by hand? Video looks pretty standard to me.
