Master cylinder with flow groove

A braking system comprising:

• a master cylinder including an inner wall defining a portion of a bore;
• a primary piston positioned within the bore;
• a secondary piston positioned within the bore and located forwardly of the primary piston;
• a primary pressure chamber within the bore and defined in part by a rear portion of the secondary piston and a forward portion of the primary piston;
• a secondary pressure chamber within the bore and defined in part by a forward portion of the secondary piston;
• a first seal extending radially outwardly from the second piston, the first seal isolating the secondary pressure chamber from a low pressure secondary area;
• a second seal extending radially outwardly from the second piston, the second seal positioned between the low pressure secondary area and the primary pressure chamber;
• a reservoir in fluid communication with the low pressure secondary area;
• and
• a first groove extending axially along the bore and positioned such that (i) when the secondary piston is in a released position, the first groove is located directly outwardly of the second seal and the reservoir is in fluid communication with the primary pressure chamber through the first groove, and (ii) when the secondary piston is in an activated position, the second seal sealingly engages the inner wall to isolate the reservoir from the primary pressure chamber.