Brian Kohn
New member
I have rebuilt the rear master cylinder on my 1987 k100 several times with same result. Rear brake locks up within 75 miles of operation . Two different bmw shops have rebuilt it with same result. They suggest replacing the master. I have checked everywhere boneyards other dealerships BMW North America all say not available any ideas on if it is the master or where I can find a replacement. The bike is in beautiful contion & runs great. Just not stopping to goop