Chrysler Repair: clutch - frequent loss of hydraulic pressure, diesel uk, hydraulic clutch

Question
Hi, I have a 02 chrysler pt cruiser2.2 crd diesel (uk spec).
August 04 clutch failure, had replacement clutch, master and slave cylinders.
Aprox 6 weeks ago started having clutch problems. Sometimes when I go to the vehicle in the morning there is no pressure at the clutch pepal. This can only be remidied by continious pumping of the pedal (300+ times) or bleeding the system. there is no fluid loss. My current mechanic cannot find any damaged pipework and is at a loss. Often seems worse after the car has done a long journey.
any ideas on cause and how to permanently remidy the problem?

Answer
Hi Nigel,
I wasn't aware of an hydraulic clutch on the PT but then I'm not into 2000 era cars yet! But I would suggest that you can have an internal leakage in any hydraulic cylinder (master or slave) such that the fluid just bypasses the piston without leaking out. Another possibility is that there is air in one or the other of them, and there is a bleed procedure for master brake cylinders that you do at the time of installation that maybe wasn't done by the original mechanic (it is essentially recyling the fluid thru a tube attached to the outlet, by pumping the piston, from the outlet back into the reservoir until the air is exhausted). I suspect there is a bleed on the slave cylinder that could also be done after the master is hooked up to the line just like on a wheel cylinder. So try bleeding and see if that fixes it, then investigate the pressure-building capability of each cylinder with a gauge (although it might be possible to do both kinds of testing at the same time.)
Good luck!
Roland