It sounds like you need more travel, or perhaps you have enough travel and some of that is being wasted with air gap between the face of the release bearing and the diaphragm fingers. Is either of these possible?
Things to verify:
- Does the slave pushrod move the same amount as the master pushrod? If not, there may be internal hydraulic losses in the master cylinder.
- Is there an air gap between the diaphragm fingers and the release bearing when at rest?
- What flywheel and clutch pressure plate are you using?
Let me know about these and I bet we'll find an answer.
