Last Saturday I had a brake failure on my 2005 K1200S while riding on the track (Buttonwillow Raceway in California). During hard braking in third gear setting up for the approaching corner, the brakes seemed to just release and the bike rolled free for about a second (perhaps 20 feet worth) - then, they locked up for an instant, enough to get the bike sliding, then released again. As I struggled through the corner, thoroughly shaken, I noticed the "brake failure" light and the "emergency triangle" light had come on. I pulled into the pits, parked the bike, then restarted it to see if the fault light had cleared. It had. So I rode the bike out to a remote section of the pits and tried the brakes - they worked fine. I tried about ten hard stops - enough to get into the ABS, and everything worked OK.
Despite the brakes seeming to work again, there was no way I was returning to the track. I took the bike to the dealer on Tuesday and explained what happened. They said they'd put the bike on the computer to analyze the situation, and that there was a recall issued on the brakes to address a problem similar to what I described. The recall fix, of course, is the "banjo bolt" designed to reduce front brake pressure and reduce the power draw on the battery during hard braking. Didn't sound to me like this was going to address my problem, but I left the bike hoping the computer would log some other sort of fault.
Today when I talked to the dealer they said the computer showed "excessive front brake pressure" as the fault, and that they had called the BMW customer representative, who seemed confident that the "banjo bolt" would fix the problem. The dealer explained that the customer rep didn't think riding on the track provided enough battery charging to replace the power drain due to hard brake use! This is ridiculous!
Before I continue, a little background. My bike now has 14,000 miles on it, and I have taken it to six track days with never any problem concerning the brakes - if track riding does not not provide enough charging, why didn't I have this problem on the first track day? And if I had run the battery down on the track, how did it miraculously recover by the time I restarted it in the pits three minutes later? This sounds to me like a failure (intermittant, of course) of the ABS/Servo Electronic Unit! The "banjo bolt" won't do a thing for that! But apparently the customer rep says "we'll try this first before we do anything else and if it happens again we'll rethink the situation." You mean I have to lose my brakes again in a critical situation and perhaps crash the next time before BMW decides to fix my brakes right?
So, my bike is still at the dealer, and I'm trying to find out more information on how to deal with this. So I call a friend of mine who bought an R1200GS about the same time I bought my K1200S. They have the same brake system. Lo and behold, he's having an identical problem with his brakes, just riding on the street! Same thing, no brakes for a second, then they lock up, then release again. And the fault would clear after stopping and restarting. (Actually I don't think the brakes are releasing, it's just the servo going offline for a second then coming back on after you've begun to squeeze harder - but that would certainly cause exactly this kind of behavior). He said it had happened several times with increasing frequency, and that his bike is at the same dealer for repair.
The dealer is also telling my friend the banjo bolt will cure the problem and he doesn't believe it either. He's also concerned about "seeing if this works" before the electronic unit is replaced.
I did call another dealer who said he has had to replace some ABS/Servo Units, so these things do fail.
This does not sound like it's an uncommon problem. Anyone else out there having this problem? Why is BMW willing to risk the lives of it's customers to save a few bucks on a recall? Or am I missing something? Is there some way this banjo bolt idea would really fix this problem? Can anyone here offer some advice?