Originally Posted by vincentone
I went ahead and finished the 3,000 mile trip by having to stop about every two hours to bleed the air out of the system and top off the reservoir. The system has no signs of leakage. I am now back in Houston and have called my dealer again and once more they tell me they have never heard of such a problem, but to bring it in and have "patience with them" until they can duplicate the problem. They say that they will not go forward on the basis of what may be written by experienced riders in ADVrider, but must diagnose the problem themselves. It is surprising BMW has not got a bulletin out on this problem; with all off the reported failures as seen on this thread alone. The problem is not only a nuisance to riders, but in certain circumstances it can create an acute safety issue.
Although this is a known issue, some shops haven't actually seen the problem. My '09 did the same thing. BMW put the wrong mineral oil in my bike so my dealer changed the master cylinder, slave cylinder and the hydraulic lines. With that done, they still bled the system five or six times before getting all the air out.
Make sure the dealership has done the brake line recall (just a repositioning of the line) and replaces the mineral oil. I think there is a bulletin out about the slave cylinder on the '09s. I'm going by my dealership today and will check.