Kawasaki Concours Forum

The C10, aka Kawasaki Concours - The Original => The Bike - C10 => Topic started by: diego092409 on April 07, 2014, 06:37:25 PM

Title: clutch master cylinder issues
Post by: diego092409 on April 07, 2014, 06:37:25 PM
I have been delayed from enjoying my winter project farkles to date because of issues I have been having with the clutch not properly disengaging.

The story begins when I accidentally nicked the upper clutch hose while I was making unscheduled repairs to the front fairing mount on the steering stem. I dutifully ordered a replacement part but after 4 weeks of it not coming, and being informed by Kawasaki dealer that none existed in the united states I followed his advice to check the local junk yards where I was able to source one.

I installed the new to me hose. It fit and it flowed. I fought getting the system bled, bought a mityvac and got it bled down but the lever still felt spongy like there is no pressure. I put a new lever on and re built the master cylinder. I re bled the system still nothing. Then I took the slave apart. Cleaned the inside twice. I re bled system and still feels mushy at the lever.

What do I do?  I am only home 1 day a week and my gf would rather be spending time with me or riding the bike than me being in the garage fighting the clutch's hydraulics.

Next Sunday I plan to do the following. Hone the slave cylinder to clean up the last of it. Make sure the master cylinder is bled before I bleed the rest of the system. Change the engine oil in case there is something (got this idea from service manual).

Anything special I should be doing?   engine starts up fine in neutral but cannot start it in gear with clutch pulled in or put it into gear running. I am at my wit's end.
Title: Re: clutch master cylinder issues
Post by: T Cro ® on April 08, 2014, 04:15:58 AM
My thought is that you have air bubbles stuck in the line somewhere; from start to finish the clutch line (s) has got to be nearest to 6 foot long with a lot of bends and fittings where air will like to collect; and a very small volume of movement in the master just sometimes will not move it down. One way to get to bubbles up and out is to pull the lever to the bar and tape in place to which you lightly tap along the length of the lines with the handle of a screwdriver etc, the tapping tends to encourage the bubbles to work their way up and out. You can also just let it sit with the handle pulled back over the course of a night or more.

Are you pumping up the master for what its worth and quickly cracking the bleeder as per the old fashion method of bleeding even with the Miti-Vac attached? This still is required... Are you sure that the clutch pusher rod is in place between the slave and the clutch? Are you sure that the master is put back together correctly after rebuilding?

Failing the above methods there is only reverse power bleeding whereas fluid is forced in at a cracked bleeder and pushed back up through the master; but this takes special tools usually only found in a brake shop.
Title: Re: clutch master cylinder issues
Post by: Jim __ on April 08, 2014, 07:27:19 AM
If everything is put back together properly, try pumping the leveler, bleed the line and close the slave nipple, then let the lever go!  Let it "snap" back open.  Make sure the reservoir cap is in place!!!  The shop manual has this tidbit in the fluid replace section for the clutch (Sec 5-5  "quickly release lever").  When I completely drained the clutch lines, I bled a hole bottle of Dot 4 thru it with no luck.  Finally found this part in the manual about letting the lever snap back and tried it.  Two bleed cycles and it was done!  Good luck.
BTW, this method along with T Cro's suggestion of strapping the lever overnight works great for the brake master cylinders, also.  The next morning, they are nice and firm.
Title: Re: clutch master cylinder issues
Post by: RFH87_Connie on April 08, 2014, 12:36:01 PM
Make sure your handle bars are turned to the right while the bike is on the center-stand so the reservior is the highest point also.  You may want to bleed by loosening the banjo bolt at the reservoir on the pressure stroke incase there is a bubble in there.  Watch out for getting the fluid on your paint!
Title: Re: clutch master cylinder issues
Post by: diego092409 on April 08, 2014, 04:23:02 PM
Will a speed bleeder on the slave cylinder help?  Will I be able to bleed with out worrying about opening and closing the bleeder?
Title: Re: clutch master cylinder issues
Post by: T Cro ® on April 08, 2014, 05:11:25 PM
Will a speed bleeder on the slave cylinder help?  Will I be able to bleed with out worrying about opening and closing the bleeder?

No you still need to work at pumping up the master till you feel resistance hold the lever in place and crack the bleeder open and closed quickly with Miti-Vac attached without letting go of the lever. If the bleeder is cracked too far open you can still suck air in past the threads.
Title: Re: clutch master cylinder issues
Post by: diego092409 on April 09, 2014, 06:43:55 PM
So, when I pull the clutch lever in over night is the bleeder cracked or closed?  I am going to change the bushing that the pin pushes against and wire tie it fast Saturday when I get home
Title: Re: clutch master cylinder issues
Post by: T Cro ® on April 09, 2014, 07:00:29 PM
So, when I pull the clutch lever in over night is the bleeder cracked or closed?  I am going to change the bushing that the pin pushes against and wire tie it fast Saturday when I get home

Closed.....
Title: Re: clutch master cylinder issues
Post by: diego092409 on April 09, 2014, 07:28:50 PM
10/4