Yeah I had the same issue, leaking fluid and it was actually leaking within the slave cylinder . I replaced the slave and it fixed the leak and the issue, I too could top off the brake fluid and it would temporarily fix the car, namely get me home from wherever I was, to the point where I had to remove my clutch stop and put the pedal to the floor completely before changing gears, to avoid grinding. Maybe your issue is different, this is my experience with it, my two cents.