Hi there,
Once I had to tow my m696 to repair shop, while towing it I think I overpressed clutch lever and just after that it started to malfunc. Once in 8-10 stops, when I press clutch lever I can't change gear to neutral and have to use brake because bike still tries to move.
I had new master cylinder and replaced stock one and hoped that it will solve issue. It did not help. This issue still happens, less powerfull but bike still drags when clutch lever pressed.
I got my self to mechanic to bleed air from system and he says that there is no air in system and that is slave cylinder malfunction. Actually there were some air just 1 or 2 bubbles and he said there is no need to bleed air as there is no air. And now he wants to check slave cylinder.
clutch plates are new.
Does my issue looks broken slave or is it air in system? my mech guy refuse to do more air bleeding as he says he know what he says and there is no air..
99% of the time, if the slave isn't leaking, it's air.
Try tying the lever back to the grip overnight.
It will allow any tiny bubbles that might be in there to rise to the master.
Check the cluthch lever to make sure that it is not engaging the clutch while it is depressed...rgds
Quote99% of the time, if the slave isn't leaking, it's air.
Try tying the lever back to the grip overnight.
There is no leakage on visible part of slave cyl. side and fluid tank is full(no liquid disappeared during these 14 days)
After overnight lever press should I bleed slave cyl bleeder or the one I have on master?
QuoteCheck the cluthch lever to make sure that it is not engaging the clutch while it is depressed...rgds
I've got adjustable lever and it does not seems to help. Clutch just engages\disengages more rapidly\slowly, "sweet spot" is wider or shorter.
Quote from: kokis on May 30, 2013, 05:27:00 AM
There is no leakage on visible part of slave cyl. side and fluid tank is full(no liquid disappeared during these 14 days)
After overnight lever press should I bleed slave cyl bleeder or the one I have on master?
I've got adjustable lever and it does not seems to help. Clutch just engages\disengages more rapidly\slowly, "sweet spot" is wider or shorter.
On the master. Any air in the system should rise to the top.
Leakage from slave will appear on the sprocket side if it is leaking.
I've heard of this tying the clutch lever to the grip trick before, but was never clear on it - do you need to take the reservoir cover off for this to work? Take note I have the old style masters that have the rubber grommet that protrude down into the reservoir.
No. No need to take the cover(s) off. Just secure the lever to the bar and let it set a while.
Any thoughts about damaging(and repair possibility) slave cyl by overpressing lever several times?
Quote from: kokis on May 30, 2013, 08:41:46 AM
Any thoughts about damaging(and repair possibility) slave cyl by overpressing lever several times?
You can't 'overpress' the lever as far as I know.
Do you think the slave traveled too far?
I don't know what to think. My tech guy says that rubber gland in slave might cracked or inverted, and liquid is not leaking coz it goes to closed loop.
I am concerning that it is air because issue happens once in 5 times and there just a little more pressure needed to unstick plates, I even can operate with gears just after engine stops without lever re-press.
I would be just a little suspicious of your mechanics thought processes.........
Quote from: SpikeC on May 30, 2013, 02:07:33 PM
I would be just a little suspicious of your mechanics thought processes.........
[leo]that is why you read this thread [beer]
ok, I pressed lever overnight. will bleed master tomorrow. will see if it help
ok, I did not noticed any single bubble while making bleeding on master cyl after 18hrs of wait time.
Quote from: kokis on May 31, 2013, 01:51:49 PM
ok, I did not noticed any single bubble while making bleeding on master cyl after 18hrs of wait time.
Does it work?
Will check tomorrow. Too rainy today in my area, don't want to be covered by mud.
Oh, When I released(I closed bleeder first) lever I heard some sound like something(in master cyl) was sucking air. I pumped lever few times and made bleeding again and there was no that sound. Don't know what it is. Master is brand new brembo.
I gave it a ride. overnight press did not helped..
So what can it be with slave cylinder?
I checked tech manual and it seems that there is nothing to disassemble.
Quote from: kokis on May 31, 2013, 03:16:13 PM
Will check tomorrow. Too rainy today in my area, don't want to be covered by mud.
Oh, When I released(I closed bleeder first) lever I heard some sound like something(in master cyl) was sucking air. I pumped lever few times and made bleeding again and there was no that sound. Don't know what it is. Master is brand new brembo.
when you tie the lever off, do not open the bleeder. If you opened the bleeder and left it overnight, you definitely got air in there.
On your current fresh bleeding, just tie the lever back and leave it overnight.
I tied lever and after 18 hrs opened bleeder. Then I closed it tightly and slowly released lever.
Don't open the bleeder. Just check fluid level and top off if necessary.
The plan is that the little tiny bubbles that are giving you fits will work their way up the line and into the master cylinder reservoir. Then no more bleeding should be necessary.
It sounds like you have one of the stubborn little bubbles that will not move with bleeding.
I do something silmilar to what these guys are stating, but a little backwards.
I had the best luck doing the following to bleed clutch...
1) Take pee cup top off.
2) Detach slave via three bolts
3) Open bleeder on/above slave and connect small tube to aim the drainage
4) Pump clutch lever while making sure the pee cup is full. If it reached the bottom, and re-introduces air, you have to start over
5) After you see no more air traveling through during clutch pumps, tape the lever completely compressed to handlebar
5) tap all parts involved, lines included with a screwdriver or whatever, something to get additional air out
6) Make sure pee cup is full before walking off
7) Leave overnight
8 ) As long as pee cup is still full, release lever
9) Put cap on pee cup
10) Tighten bleeder on slave
11) Reattach slave
I will try that again. Thanks for instructions guys!
For some reason sometimes I could not change gear on stop. Bike did not dragged at all but gearchange pedal would not move at all too. wtf [bang]
With the lever pulled and tied, I tape an old electric hair clipper (with blades removed) to the clutch or brake line I want to bleed. This helps vibrate the bubbles loose. It helps with stubborn bubbles in the line. I tend to tap the components also in the process generally.
Got the idea from ducatiz, but the method he uses is more entertaining! [laugh]
I came back to the thread to ask about tapping\vibrating lines which was said about in previous and the last answer.
What is the point of it??? When one rides a bike all lines receive a lot of vibrations and by your logics all bubbles should rise to master.
One thing I haven't seen mentioned.....on many Ducatis the banjo bolt securing the line leaving the master cylinder (clutch or brake) is often higher than the master cylinder itself. This leaves a point inside the joint where air may accumulate as it rises, but it won't naturally go down into the master cylinder and out the reservoir. Often, to remove the last obstinate bit of air you'll have to dismount the master cylinder and hold it so that the banjo fitting is lower than the rest of the master cylinder so that the air can burp out.
I've seen dozens of these, especially on brake masters, but occasionally on clutch masters.
You can break the joint (by loosening the banjo bolt), squeeze the lever and hold it, tighten the joint, then release the lever to bleed this joint, but you might not get the air out and it can lead to leaking at the joint. The method of removing the cylinder is more effective and fool-proof.
Thank you very much, will have to work with it. [leo]
Quote from: Cloner on June 04, 2013, 03:49:28 PM
One thing I haven't seen mentioned.....on many Ducatis the banjo bolt securing the line leaving the master cylinder (clutch or brake) is often higher than the master cylinder itself. This leaves a point inside the joint where air may accumulate as it rises, but it won't naturally go down into the master cylinder and out the reservoir. Often, to remove the last obstinate bit of air you'll have to dismount the master cylinder and hold it so that the banjo fitting is lower than the rest of the master cylinder so that the air can burp out.
I've seen dozens of these, especially on brake masters, but occasionally on clutch masters.
You can break the joint (by loosening the banjo bolt), squeeze the lever and hold it, tighten the joint, then release the lever to bleed this joint, but you might not get the air out and it can lead to leaking at the joint. The method of removing the cylinder is more effective and fool-proof.
This is correct. I had to do this recently. In fact the brake system would not pressurize without using every method listed in this thread, because the line was replaced allowing alot of air into the system.
There are banjo bolts with bleeders built in which work great.
The vibration method is good with the lever pulled for an hour in the garage, not on the road.