In this schematic the "Washer,oil Bolt" is used most often.
A sample from the products for the Rr. Brake Master Cylinder include: Oil Cup Comp., Connector,master, Cap,m/c, Bottom Comp..
The most reasonably priced component used on the Gl1500cf Valkyrie Interstate 2001 (1) Usa Rr. Brake Master Cylinder is the Screw,flat,4x40.