Help with hydraulic clutch diagnosis
I am hoping that someone can help me with some diagnosis. My problem relates to the hydraulic clutch on my 1999 166.
3,000 miles ago, the clutch hydraulics went soft, there was three or four inches of free travel in the pedal, and I could not fully disengage the clutch. The car went to an Alfa dealer, who diagnosed and replaced the master cylinder. The car was perfect for about 1,000 miles, until the same free travel occured again. The car went back, the clutch was bled, and all was well once again.
This problem re-occurs every 500 miles or so now, and nobody can find any fault. The car is perfect for 400 miles, then a gradual decline until I cannot disengage the clutch any more. Either the dealer or myself can bleed the clutch, and it is ok again for another 500 miles.
The thing that is really stumping me, is that there is no noticeable drop in the fluid level in the reservoir. This suggests to me that there is not really a leak, but more of an intake of air somewhere. I have had a pretty good look at the master cylinder in situ. Both the outlet to slave, and the inlet from reservoir "look" fine to me. The pipework from reservoir to master cyl routes through the bulkhead, and behind the centre console so that is hard to check.
It has been suggested to me that as there is no real leak, it must be on the 'suction' side, ie inlet into m.cyl from reservoir. It looks fine to me, but any suggestions on how to check this further - all I can think of is soapy water?
If anyone can offer any tips, or suggestions, I would be very grateful. This is proving a real puzzler for both myself, and my dealer.
ps: I am going to post a very similar message on the 164 lounge, as I imagine more 164 owners have experience of working on their cars than 166. Apologies to those that read both lounges.