In the past few months ( 3-4 months ) I've had problems with gear change because I keep getting air in the clutch hydraulic, and I ( and my mechanic ) cannot figure out how to stop this. The master cylinder was replaced with a new one, and there is nowhere to find oil leaks. When bleeding the car the issue is fixed temporarily, the pedal starts to soften slowly and after around two weeks, gear change starts to noticeably get harder, starting from reverse and/or first. Eventually I would need to press the clutch twice or even more in order to change the gear, and also at this point gear change starts to be difficult also for fourth and fifth with one clutch press.
To me this problem looks like there's no fix to it, as I don't know what else to change or replace, no oil leaks, but somehow air is getting inside the hydraulic. Anyone went through a similar issue? Any help someone can provide? Thanks!
