jovially

Hi all,
I'm a new member here researching what seems to be an old issue, but I can't find an answer because the old threads referring to this seem to have run out, so I have decided to start my own. I bought my 97 MGF last year, it always had a low clutch, engaging just off the floor. The PO had replaced both the master and slave cylinders recently and I have Rimmer receipts to prove it (they are also new and shiny!) My first thought was that there was still air in the system and that it just needed a good bleeding. It couldn't be a worn clutch, because from my own experience (and that of most on the MG community posts) is that a worn clutch has the opposite effect, ie an increasingly high biting point. No leakage in the system anywhere, and the flex line appears to be in good condition. So using my Gunson Ezeebleed, I got a few bubbles out, but on driving it I found there to be no significant improvement. I checked the release arm which appears to be free, so no seizure there. Then I decided to do some measurement of the slave piston movement, and here is the interesting part. Total movement of the slave piston rod is 14mm when connected to the release arm, but it pushes out 22mm when disconnected from the arm. My mate has a TF with a perfect clutch feel, so I got him to measure his pushrod movement, which was 20mm. So this tells me that there is still air in the hydraulics, which compresses, reducing the piston movement when under pressure, but does not when there is no resistance (or back pressure). So I decided to have another go at bleeding, I must have used 3 litres so far and still no change. I tried jacking up the rear end as far as I safely could, no difference. I tried pushing the pedal several times while the bleed nipple was open and flowing under pressure from the Ezeebleed, still no improvement, except a hint of tiny bubbles coming out after doing that. So I did it again, a dozen times, until I could get no more out.
I have fitted the MG mania slave bracket stiffener but haven't tried it yet (winter in Alberta!).
I'm still convinced that there is still air in there somewhere, but why can't I get it out? Anyone who has had similar symptoms and was able to fix the problem, I would love to hear from you before I start replacing the entire system a piece at a time!

John T, Calgary AB