A master cylinder for a hydraulic disc brake includes a housing defining a cylinder,
the cylinder having a first and second end along its axis. A piston is received
in the cylinder and has a radial seal between the piston and the cylinder. A lever
is pivotably associated with the housing for pivoting between a rest position and
an actuated position relative to the housing. A push rod is operatively associated
with the piston and the lever to move the piston axially within the cylinder as
the lever is actuated between the rest and actuated positions. A threaded engagement
between a first end of the push rod and the lever is configured to cause movement
of the rest position of the lever relative to the housing when a rotating force
is applied to the push rod causing axial rotation of the push rod. An indexing
structure is operatively associated with the push rod for providing index axial
rotation of the push rod upon application of the rotating force to the push rod
causing axial rotation of the push rod.