The most reasonably priced component used on the Gs1000s 1979 (n) Usa (e03) Front Master Cylinder is the Washer.
A sample from the products for the Front Master Cylinder include: Bolt, Piston & Cup Set, Diaphragm, Cap.
The sub assemblies and components that make up this Front Master Cylinder include this Piston & Cup Set, the most expensive part.