clutch master to slave ratio

[steve91tt]

I have been having trouble with the engage point on my clutch.

http://www.classiczcars.com/forums/showthread.php?42242-Inconsistent-engage-point-noisy-clutch

I have a theory and wanted to pass it by the experts here for comments.

I found that my slave cylinder sometimes does not release entirely. This results in a high engage point and an overworked release bearing. When it is not releasing the clutch folk in held very tightly and the clutch peddle is rigid. If I manually release the pressure on the hydraulic system then the clutch peddle is less rigid, the fork is moveable by hand and the engage point is very close to the floor. I believe that this release of hydraulic pressure also happens randomly on it's own. I think this is why I have a random high and low release point.

My theory is that the piston in the master cylinder is not returning to its stop when the peddle is released. I think that this is caused by the fact that I have the rod adjusted almost all the way to the end of the adjustment (long). If I adjust it so its shorter then the clutch won't disengage when pressed to the floor.

Could this be caused by some sort of a missmatch between the bore of the slave and the master? I thought that there was only one bore for all cars. No? Is there something else that I am missing.

Components:

240mm Center Force clutch

Aluminium Fidenza flywheel

longer clutch collar

Stock Beck Arnley master and slave

[Arne]

Steve, you've touched on something here that still puzzles me to this day. Take a look at this thread, especially starting at post #12:

http://www.classiczcars.com/forums/showthread.php?34159-Slave-Cylinder-Sizes

[steve91tt]

My master is 5/8 and slave is 3/4. From what I am reading I need the bigger master (11/16) to make things better but I can't seem to find one. Anybody know where I can get a bigger master or smaller slave?

In the mean time I removed the stops that limit the top and bottom of the peddle travel. Went for a long test drive and I now seem to have a consistently low clutch engage point with no release bearing sound. If it keeps working then good enough for now but I would like to get it fixed long term.