Another big thankyou from me. Just changed the slave cylinder, no apparent fluid loss but lost all resistance at lever when hot. Did the usual bleed etc and lever felt normal once cooled off. Problem returned when engine hot. Only when I removed the unit could I see the problem. The cylinder was a mess of encrusted old fluid from I suspect a very slight leak, this had blocked the drain hole and so there was no signs of a leak. I don't do many miles and have changed the fluid every two years. I suspect it never leaked enough between changes to cause a level problem but eventually gave up. I have no idea why the workshop manual requires engine removal, that in its self is enough to put people off doing it themselves. Once again thanks for taking the time to take great pictures and share your knowledge, Ed