sailorjerry

My set up, Brembo 16mm master, braided line, stock slave.

So here's the issue..

Thursday I low sided going about 10mph, luckily it was in my driveway, no big deal, nothing hurt. Pushed it into the garage and that was it.

A few days later I decided to change the oil and other various fluids as well as the clutch springs. Removed the clutch cover and swapped springs one by one.

I also took the time to remove the slave cylinder to check for leaks, removed push rod to check for excessive wear. No issues there.

Bled the clutch. (actually have bled it about 40 times now)

Now after everything the clutch will NOT disengage.

I took the clutch cover back off to make sure nothing was hindering clutch movement found nothing.

watched the pushrod move the clutch out be the discs still stay locked together and keeping resistance on the clutch.

When I removed the slave to check for leaks I did notice that the piston slowly crept out with out the master cylinder being depressed.

What other things can be checked? Is it possible that the slave cylinder is bad and isn't moving enough when the lever is pulled?

smokinjoe73

It seems unlikely the slave is bad based on the facts you included. It was working fine, you dumped it, then dismantled it.

Figuring you didnt ride it at all after the crash? You should check the 3 bolts that hold the slave onto the motor. When I removed mine they were very picky about being tightened equally to apply square force to the rod. I thought I had them down and even rode the bike to test it.

It felt weird so looked again to see they were not equally tight.

Also did you bleed the line from the top and the bottom? That bleeder at the bottom doesnt make much sense since bubbles rise. I had way better results cracking the banjo bolt at the top open while pumping the lever with a rag around the bolt.

You are sure the rod is in there right? Have you tried manually pushing it in to see its moving?

Any damage to the clutch cover or any components from the tip? That could relieve you of hydraulic pressure too.

sailorjerry

I did not ride after the crash, honestly didn't think much of it at the time.

Also the system is 100% properly bled. I even bled system one more time after OP.

The rod is in no bends or signs of excessive wear.

Slave cylinder is mounted tight and even.

While operating every thing with the clutch cover off, I was able to tell that the clutch seems to be moving to with in the normal operating range (as indicated by the wear marks on the basket) Could be a couple mm shy...

But I did notice that even when the clutch is disengaged, I can move the steels and fibers but they seem to be sticking together when I try to spin the wheel.

Maybe the oil bath from laying the bike over is the whole issue? But if that's the case how to fix the issue?

smokinjoe73

No way is that an issue since the whole clutch is oil bathed anyway. You are supposed to soak the plates before you install them. Plus the oil is not going to make anything stick ever.

When you pull the clutch lever in, can you push the bike to try to check engagement?

I would not rule out a hydraulic issue even if you think the system is bled. Like I asked, what if you mechanicly push the rod in? Does that disengage the clutch?

Tweety

You said the slave was slowly creeping out even with the master engaged? If that's the case, I say either the bleed isn't completed, or the slave is leaking from seal or misalignment (smokinjoe's suggestion)...

Yeah, check mechanicly that the rod actually disengages the clutch... It seems very strange, that's for sure...

sailorjerry

Joe, with the lever in I cannot move the bike.

I have not been able move the rod in mechanically, to check to see if the clutch moves any further out and allows disengagement. If you have a good way to do this I am up for sugestions.

As I stated earlier though, I did operate the clutch with the cover off and could physically watch the clutch move in and out as actuated.

I understand I cant completely rule out air in the system but with the feel I have at the lever and how many times I have rebled the system its pretty low on my list at this point.

Tweety, Yes when the lever is in the relaxed/ normal position, if the slave cylinder is removed from the bike the piston does slowly creep out on its own till it's at the end of the stroke.

But at the same time, no visible fluid leaks from around the seal, or anything hindering the movement of the piston.

and as for misalignment, I have removed and installed the slave several times and still no change.

ascothawk

You have to keep bleeding at the top banjo bolt like smokinjoe says on the second post.

sailorjerry

Just so the bleeding situation is clear.

The brembo has a bleeder on the master, so it is bled properly, the slave cylinder has a bleeder at the top, it has been bled. For good measure I cracked the banjo's at both the master and the slave. The system is bled.

Wicky

Check that fluid isn't leaking behind the cover. Have you got a gasket on the refitted slave? Did you disassemble the slave cylinder and piston and check the seal and piston & bore. If grit gets in there it can score the bore and cause a loss of pressure / slow leak.

For bleeding I use a large catheter syringe and suck it down from from the bleed nipple near the slave - make sure the reservoir is filled up little and often as if it runs slghtly low when bleeding it can introduce bubbles into the system.

sailorjerry

Wicky, due to having no issues prior to this I have not disassembled the slave to check the piston & bore, but as stated earlier there are no signs of leaks at the slave, and the gasket is intact.

Tweety

But, on the other hand, that slow creeping, is a rather distinctive sign of a slow leak, introducing air in the system... Not that it relates to the other issues... I'd check it... (caveat, gravity overrides things, so the slave should be in the same orientation as on the bike, for that to be a valid test... Even fully working, gravity will very, very slowly pull the cylinder out if you hold it with the cylinder facing down...)

As for mechanically testing... Well... Remove the slave, and use a 2x4 as a lever / pushrod and lean the bike against the wall or something with the wood piece in between... Trust me, it works, I have done it a few times to diagnose such issues... Or just use hand force, with the bike on a stand... Most likely will need a helper for that though...

xeris

Read through the thread and that highlighted statement stands out. To me it confirms the advice that you are getting.

sailorjerry

Well finally got time to work on the bike this weekend.

Took slave back off and rebuilt, this did help a little bit, especially with bleeding but it still wasn't perfect.

Removed the clutch, cleaned and soaked it and reinstalled. Now it is no longer dragging at all, clutch feel is back to 100% and the new springs make the clutch grab perfect.

Thanks for the help guys.