Empty brake fluid from a motorcycle and replace master cylinder?
Motorcycle Master Cylinder
Of course the new cylinder can get air in the line but that is the reason to bleed off that air. Best way I've found is to drain all you can out of the bottom end than replace the new master, run a clear hose from the nipple to a jar with some fresh fluid already in the jar (that keeps the air from coming back up the into the system as you pour and close off the cylinder as you bleed it out.
