Fiesta clutch fun

[Throbgrundle]

Hi all,

I'm having a fun time after replacing the clutch master cylinder on my 1998 Mk4 Fiesta. Not a difficult job you'd think, old one out, new one in and bleed the air out but not so.

First bleed was done with a pressure bleeder and seemed to work rapidly, however, every 10-20th push of the clutch pedal was met with no resistance, right to the floor. After this, it went back to normal for another 10-20 pushes. Went old school for the second bleed and got some air out but the same thing was happening and a third bleed with the pressure bleeder pushed half a litre of brake fluid through with no visible bubbles of air at the outlet but still, every so often, no resistance from the pedal and back to normal for 10-20.

Here's the fun bit though, if you're stationary and pump the pedal, no problem, you can feel the clutch resistance every time with and without the engine running. It's only after pulling away or changing gear that the pedal occasionally goes down with no feel to it at all.

Has anyone had this kind of madness before? Was it air, a knackered slave cylinder or possibly a dodgy replacement master?

Any help appreciated.