Clutch pedal drop - hot and cold
Just reading this thread and thought I'd tell you about my similar issue, which has been on and off for 6 months.
First issue was driving relatively hard on A5 with lots of roundabouts - the clutch pedal dropped lower and lower to a point I could barely change gear. I nursed it home (avoiding stopping at all costs!) and took a look - but couldn't find anything (fluid was full etc). Next day after a few pumps of the clutch it was fine. Read some threads and 'hot brake fluid leaking through' seemed to be the culprit.
Drove it for 3-4 months without issue, though I sensed it dropping a bit lower occasionally.
Just came back from France and after 3 hour drive we had some hilly back roads to navigate, found myself braking hard and using the clutch simultaneously and felt some weird fluctuations - then 5 mins later had the low clutch pedal problem. I stopped and pumped the clutch and it seem to improve.
Got up this rainy morning and before I started the car the clutch was on the floor!! I pumped it for 5 mins and got slight improvement. I started the car and pumped clutch and brakes separately and eventually the clutch came back!! Definitely not a 'hot brake fluid issue' this time.
I know my rear brakes pads are thin and discs worn - could this be linked (too much fluid required to brake perhaps?).
Is the master cylinder the master of this problem? (sorry for the sh*t pun).