The 1983 R80ST has a single front disk brake on the right side of the front wheel. It uses a Brembo caliper connected to a master cylinder and fluid reservoir built into the right handlebar control unit. I repainted the caliper using black caliper paint.
Here is what the caliper looked like when I got the bike removed it from the bike.
As Found: Front Brembo Disk Brake Caliper And Missing Brake Rotor
Brembo Front Brake Caliper With Crusty Looking Brake Pads
And this is how it looks after repainting and rebuilding.
Brembo Front Caliper After Rebuilding
Brembo Front Caliper After Rebuilding
Brembo Front Caliper After Rebuilding
This shows how I do the work.
Here is a short video summarizing the procedure. It is a mix of video from the 1983 R100RS and 1983 R80ST.
VIDEO: 1983 BMW R80ST Rebuild Front Brake Caliper