Clutch Master Cylinder Diagnosis

[flat16]

Hi,

My car's been standing for 9 years and has recently been re-commissioned. The brakes seem pretty good and it stops in a straight line. However, the clutch has gone to the floor a few times now... It has a new slave clutch cylinder.

I was told the definitive way to test a Master Cyl is to floor the clutch for a few minutes and see if it bounces back. I've done this many times and there's no problem. The clutch seems to go to the floor randomly. It either works perfectly, or goes to the floor. Pumping the pedal doesn't seem to affect it - it comes back on its own accord.

How can I definitively trace this to the Master Cyl? Could it be air in the system? I've bled it and the mechanic also said he bled it when he fitted the slave.

If the Master's on its way out, will I be able to see traces of fluid around the seals?

Thanks in advance.

Edited by flat16 on Wednesday 15th July 12:47

[Pumaracing]

No it couldn't be air in the system. That would give a spongy pedal but it would be consistent not variable. If the slave has been replaced then it's the master. After 9 years stood unused it's not that surprising. Bite the bullet.