Just home from from a short ride. Came down from highway speed and felt the rear brake was dragging. Managed to nurse it home a couple of miles and found brake lights were on. Parked bike and shut off. Left for a bit and found that front was good and nothing at all now at back. ABS seems to cycle when key turns on and when I do the forward motion light goes out as it's supposed to but still no back brake now. Suggestions or ideas? 2002 1200LT. 46,000 miles. Just bought it and is my first BMW bike. Help if you can. Thanks.