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Cannot Bleed Clutch Slave


Nicholr

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7 hours ago, docc said:

That would awesome if an overfull reservoir could be the issue. (I've never heard of that). Otherwise, easy enough to service the lever and pivot.

Will the lever travel misbehave pulling and releasing it just sitting with the bike off, or does it have to be rolling for it to occur?

Being trained by dad the pilot, and having  a few years' experience in tooling at one of the aircraft builders in Seattle (Ahem!), everything was cleaned beyond shop mechanic's level, visually compared (MG to aftermarket), OEM adjustment screws were swapped over, all fit was checked, and Mobil1 synthetic grease used in assembly. Oddly, it functioned perfectly for several months of local and interstate blasting. The only variable that comes immediately to mind is heat(?) I produced a few extra BTUs in teaching junior a lesson. Since cooling down, the lever feels as before. However, I recall that I am under a Gypsy curse, having failed to give money to some flamboyantly-dressed females along the Autostrada in 1985. Or do those curses have an expiration date? 

Anyway, after I use one of my surplus (new) syringes to suck some fluid out, I think I'll do the old trick of banding the lever to the bar and letting it sit, with the bars turned so that the M/C and reservoir are the high point.

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8 hours ago, docc said:

That would awesome if an overfull reservoir could be the issue. (I've never heard of that). Otherwise, easy enough to service the lever and pivot.

Will the lever travel misbehave pulling and releasing it just sitting with the bike off, or does it have to be rolling for it to occur?

Here's how it works docc if it is indeed the case here. An overfull reservoir leaves no room for fluid expansion so you can sometimes to an extent get away with it until it gets warm/hot. So if the reservoir is overfilled when you pull the lever it will as usual squirt a little fluid back into the reservoir until the secondary seal is exposed to the fluid and the fluid connection hole is covered. The problem is now the reservoir is totally full and when the clutch springs/spring tries to back drive the master the master cant push the fluid back into the reservoir because there is no available room for the displaced fluid to return. Your hand pulling the clutch lever generates more force than the pressure plate springs trying to return the system to the null position so even with the system totally full the hand force can create enough expansion in the reservoir (up to a point) that allows disengagement but then there's not enough force from the pressure plate springs to do the opposite.

If you were aware of what was about to occur you would probably have noticed the pull of the lever when the sticking clutch event occurred was harder than normal. The Focus I drive has had similar issues with the clutch for other owners, not I ( pedal sticks to the floor and a hard pedal for the first operation after a freeway drive without using the clutch for a while) and the dealers were replacing clutches and master cylinders and slave cylinders etc only to have the condition re occur. When I investigated my car and another one both reservoirs were way over filled from the factory. They have cast into the reservoir an arrow pointing down with a line above the arrow and the word "full" so everyone fills to the "line" which is in fact over full. When you fill to the arrow tip that's the full level and leaves expansion room. I dont think there's been a single event since i mentioned this on a forum. The natural thought is to "fill to the line" which in this case is wrong.

The hard pedal push after a run without clutch use is due to the fluid heating up and expanding. Its a bit like the mal adjusted brake lever freeplay issue.

Is this the issue here? don't know but its an easy place to start.

Ciao

  

       

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