My 77 has just developed difficulty shiting into gears. (5 speed) It is classic signs of a failing slave cylinder except no leakage anywhere. The master is still full.

Questions:

Is this a simple pedal adjustment? If so, adjust closer to floor?

Could the fluid be too old and broken down?

Clutch cylinders (especially the master, but also the slave) can leak past the seal internally - no external leaks seen. I would probably replace both master and slave as a pair. (I've never had success replacing only one or the other, the old one always fails shortly after replacing the first.) I'm betting this will fix your problem.

Arne, you're probably right. What about the fluid level still being full?

One other note. The slave cylinder can be easily depressed by hand.

Arne, you're probably right. What about the fluid level still being full?

Internal by-passing in the master cylinder will not affect the fluid level. It will stay full. What is probably happening is that the master cylinder piston seals are leaking, and so not enough fluid is being pushed to the slave.

Edited April 24, 201115 yr by Arne
typo fix

That makes sense. Thanks.