Clutch acting up

[Wasta]

Last year I was out for a ride and got clutch issues, as I remember the biting point seemed to move closer to the bars and got worse as I headed home. I ended up putting the adjuster between settings to push the lever out and away from the bars, this worked and got me home.
I checked fluid levels and all seems good.

Anyone had this problem before?

I intend to replace the clutch friction plates and probably the slave cylinder.


Anyone have either of the above items for sale?

[Nasher]

This might help:
https://www.ducatiforum.co.uk/thread...s-carby.91609/

[slob]

how long has the fluid been in the system. lever too close to the bar sounds like clutch dragging rather than slipping (although i had a few drinks this afternoon) water boiling out of old fluid would cause this.

[Wasta]

Thanks for the link Nasher.
The fluid had been replaced a few weeks before the problem happened Slob.

[Albie]

You have air still in your system needs flushing out. One less laborious way is to over night remove the lid then pump until you get some pressure the cable tie the lever back over night. The air should try to escape. Failing that a pump or try it all over again.

[Wasta]

Originally Posted by Albie

You have air still in your system needs flushing out. One less laborious way is to over night remove the lid then pump until you get some pressure the cable tie the lever back over night. The air should try to escape. Failing that a pump or try it all over again.

I'll give that a try Albie, it's worked before on the brakes. I had done 150 odd miles after bleeding new fluid into the clutch before the problem started.

[Mr Gazza]

It sounds like air in the system, but not sure why that should manifest 150 miles on after bleeding. Is the bleed nipple tight and seated nicely? I always put a little PTFE round the thread these days although that is more to assist with bleeding as air can pass down the thread while you're bleeding sometimes.
I find the best way to remove residual air from the clutch is to caress the lever with the res. lid off. You can often see little streams of bubbles rise from the feed hole. Just short lever strokes are enough, not so much as to even move the clutch. On the coffin types you can see the piston moving through the feed hole.

I'm not sure about the holding the lever back overnight method, but it will pressurise your slave and find any fluid leaks that might be a possibility.
Unfortunately the fluid takes the paint off the cases round the slave when they leak, so be aware of that and check round there asap. Remove the sprocket cover for a better view.

Another thing that occurs to me is that the slave mounting screws could be loose? Unlikely but worth a check anyway.

[Albie]

Originally Posted by Wasta

I'll give that a try Albie, it's worked before on the brakes. I had done 150 odd miles after bleeding new fluid into the clutch before the problem started.

Well now I have the use of an air assist unit at work it's easy but.....the other day I learnt a trick that comes from the pits. With the lid removed turn the bars so the edge is upwards angle. Pull the lever back and let go. Repeat and rest say after 10 goes. Everytime it does the back to normal it should shock a bubble of air. It really does work. This was on a brake but exactly the same. After 5 minutes the lever worked really well. It's not a service routine just a quick race trick.

[Mr Gazza]

I find that gentle short strokes of the lever work just as well. You need to watch out for little jets of fluid jumping out of the reservoir if you're going to get violent!
I have found that you can help the air upwards by tapping the line with a spanner or something. Different strokes eh?

[Albie]

Originally Posted by Mr Gazza

I find that gentle short strokes of the lever work just as well. You need to watch out for little jets of fluid jumping out of the reservoir if you're going to get violent!
I have found that you can help the air upwards by tapping the line with a spanner or something. Different strokes eh?

No violence used just more of a flick release. Whenever I top up or bleed clutch and brakes I always protect surfaces anyhow it's what I do whether extreme or not.

[Darren69]

If you can't generate any pressure in the system by pulling the lever then
leaving it pulled overnight will not work? I think that's a myth and one that would only work in certain circumstances. It will only work if you have some pressure in the system, if you have none then it will do nothing.Your best bet for quick air removal is to bleed it from the master cylinder end using the banjo bolt at the master cylinder end or as fitted to some later masters the bleed nipple that was fiitted with this in mind. Otherwise it is easier to reverse bleed as air will more easily travel up than down.

[Dukedesmo]

I find that Ducati clutch systems can be a pain to bleed as you can't get the pressure as you would in a brake system due to the slave moving freely and not up against a dead stop.

I found that when fitting a new full clutch system i.e. slave/master/line etc. it was much easier to fill from the slave end upwards using a large syringe as it naturally pushes the bubbles upwards whilst filling - not sure how much help that is in a 'full' system though?

However if your clutch was working OK and then, suddenly doesn't get the plate separation that it sounds like something else is amiss.

Would advise you check that the clutch hub hasn't moved outwards and having lateral play, usually due to the star washer eating into it or even the hub nut coming undone, I've had both happen on my 916.

When the hub nut came loose it actually ended up 'ejecting' the hub, plates and cush rubbers through the fairing, leaving me stranded and picking bits off the road. Happened on the first ride out after a dealer had fitted a new clutch, they told me "the 'O' ring had let go"

(I have to say I find that hard to believe when torque setting is 180nm or so but after they'd repaired it (and fitted a new side fairing and clutch cover) I finally made the decision to stop going to dealers/bike shops for repair or service.)

I also had the hub 'eaten' away by the star washer meaning it can move a couple of mm away from the basket resulting in insufficient clutch action and the pressure plate rubbing on the cover - apparently this is quite common as the cush drives allows this movement where the star washer rubs lightly on the face of the hub.

I've read recommendations of applying a light film of grease under the washer to help prevent wear? another solution is to replace the OEM hub with a billet unit that has no cush rubbers and so eliminates the problem whilst saving some weight.

[Mr Gazza]

Originally Posted by Albie

No violence used ...

How wrong of me to even suggest you are given to violence Albie..
Agreed on covering everything. I have an old shower curtain that I use and only leave the reservoir exposed.

[Albie]

Originally Posted by Mr Gazza

How wrong of me to even suggest you are given to violence Albie..
Agreed on covering everything. I have an old shower curtain that I use and only leave the reservoir exposed.

Lol : I get told sometimes to give it a bit more oomph but I take much care whenever possible.

[Wasta]

I'm not going to get time until the weekend but will explore your methods of bleeding the system again.