I’m converting this RS model to a RT. The only difference in the brake system is the length of the hose from the front master cylinder to the front brake line manifold underneath the gas tank (RT: Part# 34 32 1 241 565; RS: Part# 34 32 1 241 564). Since the RT handlebars are wider, that hose is longer. The rear brake system is the same on both the RS and RT models.
Here is a link to the documentation of how I do this work.
And this is a short video summarizing the procedure.
VIDEO: 1983 BMW R100RS/RT Install Front Brake System
I previously rebuilt the two front and one rear calipers and rebuilt the rear master cylinder. The front master cylinder was so badly corroded that I replaced it along with the entire right handlebar perch. I also installed the three disk brake rotors on the newly powder coated wheels. You can read about how I did that work here.
- 34 BMW 1983 R100RS Disassemble, Inspect & Rebuild Brembo Brake Calipers
- 34 BMW 1983 R100RS Disassemble, Inspect & Rebuild Master Cylinders
- 34 BMW 1983 R100RS Remove, Refinish, Install Disk Brake Rotors
Here is the link to showing how I install the rear brake system.
I opted to use the mechanical front brake switch that mounts in the right perch instead of the original brake fluid pressure switch that mounts on the rear of the front brake manifold under the gas tank. The hole in the pressure switch can trap an air bubble making it more difficult to bleed the brakes.
I plugged the rear hole in the front brake line manifold where the front brake light pressure switch mounts. McMaster-Carr sells a plug with copper crush washer that’s perfect for this.
I now have brakes and the bike is getting pretty close to being finished.