Clutch problems?
 

Hi,

I usually like to use only 2 fingers to action the clutch lever and this has become a problem lately. (Ducati 916)

I had the clutch standard adjustable lever set at position 2 and with 2 fingers it released the clutch without problems. I noticed lately that it became harder to get it into neutral with the lever pressed by only 2 fingers (with the lever pushed completely it's ok)- kinda like i needed to press it even closer to the handlebar. I bleeded the clutch/changed fluid to brand new DOT5.1 and it still does the same, (pressed at the same position as before seems like it doesn't disengage the clutch properly...). I don;t want to put the lever at position 1 cause it's to far and i cannot reach it

Is this due to the clutch plates or pressure plate running out??

Or this could be a fault somewhere at the clutch master cylinder (slave cylinder is new - 998 revised model with newer model clutch rod fitted)?

Please advise ,

Many thanks
Cipi

PS: Forget to mentioned, but i crashed the bike and i changed the clutch drum/center/plates/pressure plate with some used ones (plates are ok). Springs are brand new, but the rest are used

[Edited on 15-4-2006 by CipiVTS]

have you adjusted your chain recently ? if not give that a try. You can then go onto checking the clutch plates, master cylinder / seals etc.

Having clutch plates of differing rates of wear will not help either, they offer differing clearances, so change them for a new set, or of an equal mileage..ie the old ones if they are avail

Hi Demon,

i will have to change the chain cause it's quite worn + the front sprocket cause it's missing a few teeth.

For the clutch, i will definately going to get a new assembly, but i think something is wrong with the lever. When you press it has some freeplay, i checked other Ducati's and the lever is really stiff and when pressed it immediately engages the clutch.

Mine has at least 1cm of freeplay and then it starts to engage the clutch. I changed the fluid and bled it and it still has it...

Can it be something wrong with the master cylinder?

cipi, I have clutch master, line to slave, slave cyl and 748R slipper all for sale. Now isn't that a stroke of luck U2U me if interested, details in 'market place'.

Thanks Ray, but my clutch slave cylinder is new and is the newer type so my problem is elswere.

Finally the issue is after riding at high speeds (200kmh) for a few minutes the clutch lever is dead and it engages very close to the handlebar. I have to press it a couple of times till it gets firm again. After a few more miles it becomes worse again. I checked the pressure plate bearing and it moves freely and ok. Rod is greased, i have no fluid leaks.

What can it be?

I was having just this problem a few weeks ago and I ended up doing clutchless changes for the last 50 miles of a Good Friday rideout. I've since changed the fluid and it has got better, but having said that, I haven't really ridden the bike hard since then - however, it's still not perfect and a bit of high speed running tends to bring the biting point a little further back towards the bar.

I'll watch the advice with interest. I have my own ideas as to what is causing the problem, but I'm a self-confessed numpty, so I'll keep my gob shut!

I checked your posts as well and i will flush the system again tomorrow and put some fresh DOT5.1 fluid. It has a higher boiling point than the DOT4.

It's so frustrating cause i have a friend with a 998 and can you imagine he changed the fluid only once in 10000 km... i envy these guys.

Did you find the use of the adjustable pin that actions the piston of the pump at the lever???

nope - no-one answered that question :(

i didn't push it too much because i've posted that many questions recently, i was beginning to feel like a bit of a twit :P

i'm still a bit puzzled as to what is causing my/our problems. i have a new slave cyl piston, a new release bearing, a vented cover (keep the temp down a bit?) and some new fluid to chuck at the bike, so hopefully that will clear it up once and for all. i'll also check the tightness of the nut and pull out the pushrod, just to make sure it's not bent or broken. failing that, i have a bucket full of petrol left over.......;)

Cipi,

The almighty Shazam wrote something useful on this.

Apart from the system being prone to water ingress, and needing regular bleeding, another factor can cause the clutch to "go away" after hard use.

The clutch pushrod pushes against a bearing in the pressure plate.

If the bearing is not spinning perfectly, the pushrod can spin in its tunnel. When it spins, to gradually pushes the piston in the slave cylinder back in its housing so, the next time you use the clutch - nada. A few pumps on the lever helps to get it back into position, but this is not easy when your braking for a hairpin and trying to change down at the same time.

It is worse with an aftermarket slave cylinder, because the travel of the pushrod is reduced.

BTW - I run a 998, and this is a recurring problem for me too.

Good luck sorting it - I'm considering a Thorsten mechanical conversion.

Spin

I think i start to feel the same as you mentioned...

By the way i have the newer type of Ducati slave cylinder (one with a star/torx model on it) and i replace the master cylinder and the lever with another one and it still does the same.

So, in my oppinion:

1. We should completely flush the system, fit new fluid and bleed from the master cylinder banjo bolt as well as the slave bleed nipple.

2. If the pressure plate bearing moves very freely while cold, can it stick when it gets hot or rotated at high speeds?

thanks

You seem to have done a lot of "work" to your clutch area. You say you have a new "later" type slave cylinder, and i believe your bike is a 916?.............dont you need the slightly longer push rod for that new slave..............?

This would account for pumping the lever then it works.....your are in effect taking up the slack of the shorter push rod!

[Edited on 3-5-2006 by andyb]

I have the longer rod fitted of course!!:)

is your push rod spining when the bike is runing? it should not.;)

Once you've checked out the above, try doing a couple more things.

First of all, with your clutch hydraulics air can get trapped at the top of the system quite easily so you might need to bleed it from the master cylinder end. You can do this by fitting a banjo with a bleed nipple on it, or do what I do and get loads of absorbent rag around everything close to the master cylinder, then just crack the banjo open until the fluid can just seep through. Pull the clutch lever in slowly otherwise fluid will jet out everywhere, hold the lever to the bar and nip the banjo up again before letting the lever go. Do this two or three times and all the air should be out of the master cylinder.

Second, clutches are harder to bleed than brakes because, unlike brakes, the slave cylinder will move and start to actuate the clutch even with a bit of air in the system, so I've found that you need to 'prime' the slave cylinder by taking the slave off the bike, pulling the clutch lever in slowly to drive the slave piston out a little way, then push the slave piston back with your thumb as you crack open the bleed nipple - I've got quite a bit of air out this way.

If all else fails, leave the slave cylinder off and reverse bleed the system by doing the 'pushing the slave piston back' bit and cracking the banjo at the master end as well (obviously nipping the banjo up again before letting the slave piston go.

got one of these the other day to help with the next bleed.

http://cgi.ebay.co.uk/ws/eBayISAPI.d...MEWN%3AIT&rd=1

on a different note(s) - am i correct in thinking dot 5.1 won't damage paint? is it ok to use in my 748?

ta :)

Shurely something doesn't add up here? :o

What exactly?