Clutch - Slave Cylinder question.
 

Quick question regarding a clutch issue on my 2001 748S.

Clutch lever became soft and difficult to change gear, then lever went straight back to the bar.

I bled out all the old grey clutch fluid but no better. (lever still goes back to the bar)

So I'm thinking slave cylinder - take it off and then here's the question.

The clutch lever is now rock solid although there is no movement at the slave . (if I put a drill bit in the hole it does not move when operating the lever)

Put it back on the bike and the lever goes back to the bar again.

I'm thinking the slave is 'locked/siezed' or the seals have gone and fluid s just rushing past them.

Any opinions on other possible issues before I have to go shopping for a new slave cylinder?