Ok guys,
4 days ago while driving my daughter and a friend home from a nightclub i noticed the clutch pedal felt odd, eventually it stayed down when pressed and we were stuck (8 hours for AA to get to us!!)
Fluid level was on the minimum mark so the system was inspected, no leaks anywhere, no drips from weephole in clutch housing, nothing from the back of the master sylinder in cabin either!. AA guy said that as the fluid was low and rear brake pads are very low (brakes and clutch share the same fluid reservoir) it had probably sucked a bubble of air on a steep hill or bend. So it was topped up and the clutch bled, everything seemed ok.
Last night same thing again driving girls home again, I had bought a litre of brake fluid so I checked the reservoir, still full!! then jumped underneath and we bled the clutch thoroughly.
Nice hard pedal and off we go, after about 45 clutch presses same scenario and van is immobile!
In summary, air is entering system but no fluid loss and no leaks, seems obvious that it is sucking air in somewhere but how the hell do you find that?
Anyone else got other ideas or advice??