Patent ID: 8209977

Claim:
A fast-fill braking system comprising: a master cylinder; a bore structure including a first wall portion that defines a first chamber within the master cylinder having a first diameter and a second wall portion that defines a second chamber within the master cylinder located forward of the first chamber having a second diameter that is smaller than the first diameter; a fast-fill piston slidably received within the first chamber and is configured to move with respect to the first chamber between a rearward position and a forward position, the fast-fill piston including an inner wall portion that defines an interior chamber and a front wall portion that defines a front opening into the interior chamber; a primary piston slidably received within the interior chamber and configured to move with respect to the fast-fill piston between a retracted position and an extended position when the fast-fill piston is in the forward position; and a secondary piston slidably received within the second chamber, wherein the first wall portion and the second wall portion define a sealing lip therebetween; wherein the fast-fill piston and the primary piston are each spaced apart from the second wall portion and the sealing lip when the fast-fill piston is in the rearward position; and wherein the front wall portion of the fast-fill piston is positioned in sealing engagement with the sealing lip when the fast-fill piston is in the forward position such that the interior chamber forms a pressure chamber that leads to the secondary chamber.