Ok decided to try a process of ilimination B4 spending more money. I put the Original Slave Clylinder back on and headed off to over to Blackpool a round trip of 50 or so miles. I made a point of going through Town just to use the clutch more and try to encorage failier.
Turns out it ran fine and lost no pressure at all. Clearly a Faulty Oversized Cylinder.
Weather permiting i'll take it out again tomorrow

But did you rebleed the system when you fitted the original slave cylinder back on?

Darren

I got an over sized slave from Motowheels for the 996 and the seals on that were leaking immediately but you could see it around the slave where it bolts on to the crank case.

Rang em and they sent me new seals to put in and it was great like that for two years until the pushrod end bearing seized and snapped the pushrod too.

Thought it was going to Cornerspeed?

Had its 12k service with Cornerspeed last week, Picked it up, Got as far as Matlock when i lost Cluch pressure. Called the AA who bled it up again which got me back to Cornerspeed, Neil took some time out to have a look at it and to be fair none of use could pin point the exact problem. So seeing as it was late and i had 100+ mile jorney home we Bled it again to make sure it would last till I hit the M1 where I just stuck it in 6th and headed for home.

Neil will have checked all my options then so you have only one left in my book.

Master cylinder problem?

No easy way to check other than replacement?

Hope you get it sorted.