S4R - Clutch Lever Went Completely Limp

[JimmyTheDriver]

Hey fellas,

*Edit* This all started since I moved the bike in the back of a moving truck a month ago.  I know the level was knocked slightly upward by a box and I pushed it back down.

Over the past few weeks, the clutch pull on my 2007 S4R has gotten pretty tough.  I noticed my hands getting sore after a few blocks.  It felt like there was a good bit of friction in the lever and a squeak coming from both the lever/master and potentially the slave.  Thinking I knew what do do, I popped the lever off the master assembly, and am now left with an inoperable bike.  When I took it off, I cleaned off some of the dirty grease, added a small bit, and tried to put it back in.  The little push pin wouldn't set in the rubber boot all that well, and eveything just looked... weird.  Once I thought I had it re-assembled, there was no pressure on the lever and the bike was unable to shift.  The rubber boot looked pressed in.

Is there a trick to this?  Do I need to bleed?  I literally know nothing about this assembly (lever, master, slave) so any advice would be great.

If it helps...


Thanks
Jim

[JimmyTheDriver]

Bump to get a bike on the road!

[ducpainter]

It looks like the piston is stuck in.

Where is the boot?

[ducatiz]

i would disassemble it to make sure the seals/piston are good.  the pistons can rust and there is a return spring too.

lube it all up well with brake assembly lube and try again. 

[thought]

Anytime there is something wrong with the clutch or brake feel I always bleed first.  Most times it fixes the issue and after that I start thinking about how much it's going to cost me if that didnt fix it.

Not sure what else do after that doesnt work though.

[JimmyTheDriver]

It looks like the piston is stuck in.

Where is the boot?

The boot is in the pic.  Maybe this one is better?



When I try to reassemble and pull in lever, there is no friction until the lever is virtually touching the grips, and then the boot is extremely squished in there.

Maybe Ill go the bleed route first.  How tough is the complete dis assembly?  Anything to keep it out of the shop.

-Jim

[ducpainter]

Yeah...

that looks better.

It makes no sense that it would work and then suddenly not work just because you removed the lever.

I guess bleeding is in order.

[ducatiz]

How tough is the complete dis assembly?  Anything to keep it out of the shop.

-Jim

that's a small bolt/ axial master right?

everything comes out that hole -- a snap ring holds it in.  they are plain type, hard(er) to get out.  i swapped mine with the standard type so i can use a pin tool.

once you take the ring off, you push a pin thru the banjo bolt hole and push everything out.  you can't really hurt the base of the piston unless its a plastic version (later ones are plastic).  the seals on on the piston itself and there is a spring behind it.

i use brake assembly lube, the silicone grease stuff, and lightly cover the spring and piston and slather it on the orings.  the grease will remain in place to reject moisture over a longer time than not being covered. it has to be a very thin coating tho.

[JimmyTheDriver]

So I went to bleed today, using instructions in the link, and am stumped.

http://www.speedzilla.com/forums/ducati-supersport/3431-clutch-bleeding-tips.html#post26375

Below is what I see... I don't have anything to "push in" on the slave and what I thought was the piston is stuck in the clutch assembly, not attached to the slave.  Does anything look out of whack here?  Also noticed the rubber on the master is cracked.  The clutch lever has absolutely no pressure behind it.

[Slide Panda]

There's a piston in there you'll just need something to push it in with. You can draw the push rod out carefully and use it to push the slave piston back in

[JimmyTheDriver]

Appreciate the help!

It just looks like a hole.  There is something to push in there?  I stuck a screwdriver point in there to try and push whatever it is, in... felt like I almost hit the back of it.  Push harder?

When you say push rod, you mean the rod sticking out of the engine?  I tried to give it a grab.  The only movement it has is that it can spin.  How does it come out?

Thanks!
Jim

[Slide Panda]

Yes, the rod coming out of the engine. It simply passes through to the pressure plate and inserts to a sleeve that in turn inserts to the bearing in the center of the pressure plate. You should be able to draw it out with minimal tugging. THough if you have an open clutch, they can get cruddy and bound up. Happened to my 900.

If That's the case you can open up the clutch side and remove the pressure plate and pull it out that way. If you do that, take the time to check the bearing on the pressure plate, they do need replacement from time to time. Some penetrating oil (Deep Creep, PB Blaster etc) and a soak should help free the push rod. Nothing like a screw holds it in place, it's just a light press fit.

Wtth the rod, you should be able to push the piston back into the slave - given that it's not already all the way in. It may help to open the bleeder when pushing to ensure the system is not locked up. Just be ready for the mess if you don't have a hose connected.

The hole you can see from the outside is a pass through to the slave piston that moves when you pull the clutch lever. Pulling the lever forces fluid into the slave pushing the piston -> push rod-> pressure plate -> springs. When you release the lever the springs push -> pressure plate -> push rod -> slave piston and fluid moves back up to the master.

[JimmyTheDriver]

Thanks Slide Panda -

Got it all bled and it works again.

The slave still has a horrid squeek.. feels like it's going bad, but I'm starting a new thread for that.

Thanks again,
Jim

[Slide Panda]

Cool.  Was probably something like an air bubble that formed from tiny ones into one big one that was up in the master blocking normal fluid paths. Happens from time to time.

My rule on clutch issues in the absence of any obvious external cause - bleed the hell out of it, strap the lever to the bar over night and see whats what the next day.

[JimmyTheDriver]

Yep, I did basically that.

1) Opened pee cup
2) Detached slave from motor
3) Put rubber tube on slave bleeder and put end of tube in bottle
4) Opened slave valve (never had to open master valve)
5) Used clutch push rod to push slave piston all the way in
6) Filled pee cup with dot4 and kept it full throughout the process.  If it hits bottom, air will be introduced and have to start over
7) Pumped clutch lever over and over and over and over, each pump pushed oil through the lines and out the valve on the slave
Used almost a full bottle of dot4 to make sure I pushed most air out
9) Strapped clutch lever to bar and let sit for 8 hours.  Within seconds of it being held there, tons of additional air came out valve
10) Tapped entire system with end of screwdriver to knock out any additional bubbles
11) Closed pee cup
12) Closed slave valve

Thanks!
Jim