A hydraulic brake assembly (12) includes a housing (24) having first and second side-by-side bores (30), each defining a respective master cylinder assembly. Each master cylinder assembly includes a master cylinder piston (32) slidably movable by actuation of a respective brake pedal (18a, 18b) to and between an active position and an inactive position. A spool (74) slidably disposed within a piston bore (70) of the master cylinder piston (32) is operable in a first mode to direct hydraulic fluid from a quick-fill chamber (62) to a master cylinder chamber (50) at a first pressure upon initial movement of the master cylinder piston (32) from the inactive position toward the active position. The spool (74) is operable in a second mode to direct hydraulic fluid from the quick-fill chamber (62) to a tank (20) when pressure in the master cylinder chamber (50) reaches a predefined threshold.

A hydraulic brake assembly (12) includes a housing (24) having first and second side-by-side bores (30), each defining a respective master cylinder assembly. Each master cylinder assembly includes a master cylinder piston (32) slidably movable by actuation of a respective brake pedal (18a, 18b) to and between an active position and an inactive position. A spool (74) slidably disposed within a piston bore (70) of the master cylinder piston (32) is operable in a first mode to direct hydraulic fluid from a quick-fill chamber (62) to a master cylinder chamber (50) at a first pressure upon initial movement of the master cylinder piston (32) from the inactive position toward the active position. The spool (74) is operable in a second mode to direct hydraulic fluid from the quick-fill chamber (62) to a tank (20) when pressure in the master cylinder chamber (50) reaches a predefined threshold.

A hydraulic control valve for an ATV or motorcycle takes hydraulic input from a hand brake lever as an input to a first cavity of the control valve with a movable piston therein, and from a foot brake lever as an input to a second cavity of the control valve with a movable piston therein, with the two pistons being linked. A bypass channel extends around the piston in the first cavity, which is closed off when the first piston moves longitudinally. The output of the first cavity hydraulically controls braking of the front wheel(s). The foot brake lever also pressurizes a direct line to brake the rear wheel(s) that doesn't go through the control valve.

A hydraulic control valve for an ATV or motorcycle takes hydraulic input from a hand brake lever as an input to a first cavity of the control valve with a movable piston therein, and from a foot brake lever as an input to a second cavity of the control valve with a movable piston therein, with the two pistons being linked. A bypass channel extends around the piston in the first cavity, which is closed off when the first piston moves longitudinally. The output of the first cavity hydraulically controls braking of the front wheel(s). The foot brake lever also pressurizes a direct line to brake the rear wheel(s) that doesn't go through the control valve.

A master brake cylinder includes a unique mounting arrangement for securing thereof to a firewall of a vehicle and a particular porting arrangement. A cylinder sleeve includes a series of ports that cooperate with movement of the piston allowing for by-passing of the piston at one end position and then movement of the piston past the ports for brake actuation. Additionally a two stage pressure intensifier is provided that is in-line between a master brake cylinder and brake pistons. The intensifier also includes a by-pass position at one end of the movable piston having a differential area between a forward and a rear face of the piston.

A master brake cylinder includes a unique mounting arrangement for securing thereof to a firewall of a vehicle and a particular porting arrangement. A cylinder sleeve includes a series of ports that cooperate with movement of the piston allowing for by-passing of the piston at one end position and then movement of the piston past the ports for brake actuation. Additionally a two stage pressure intensifier is provided that is in-line between a master brake cylinder and brake pistons. The intensifier also includes a by-pass position at one end of the movable piston having a differential area between a forward and a rear face of the piston.

Disclosed herein is a master cylinder. The master cylinder according to the present embodiment includes a hydraulic block provided with a main bore formed therein in an axial direction, a first piston having one side inserted into the main bore to be displaceable and the other side exposed to an outside of the hydraulic block and connected to a brake pedal, a mounting block provided with a sub bore formed therein in the axial direction and the sub bore where the first piston is inserted thereinto to be displaceable and passes therethrough and a connection port connecting the sub bore and a reservoir, a cap provided on one side of the first piston, and a gap flow path formed by a gap between the first piston and the cap so that a first liquid pressure chamber partitioned by the first piston communicates with the connection port on the main bore.

An electronic brake system and a method for operating the same are disclosed. The electronic brake system includes an integrated master cylinder, a hydraulic-pressure supply device, and a hydraulic control unit. The integrated master cylinder allows a brake fluid to be discharged based on displacement of a brake pedal and at the same time provides proper pedal feel for the user. The hydraulic-pressure supply device generates hydraulic pressure by operating a hydraulic piston in response to an electrical signal that is output in response to displacement of the brake pedal. The hydraulic control unit controls hydraulic pressure of brake fluid supplied to respective wheel cylinders. The electronic brake system operates in different ways according to a normal operation mode and an abnormal operation mode.

An all-terrain vehicle is disclosed having a braking system with an anti-lock braking control module and a first brake master cylinder hydraulically coupled to the anti-lock braking control module. A first brake actuator is coupled to the first brake master cylinder and a brake caliper is coupled to at least some of the ground engaging members. The first brake master cylinder upon actuation provides anti-lock braking to either the first or second ground engaging members. A second brake master cylinder is hydraulically coupled to the anti-lock braking control module. A second brake actuator is coupled to the second brake master cylinder and a brake caliper is coupled to at least some of the ground engaging members. The second brake master cylinder upon actuation provides anti-lock braking to either the first or second ground engaging members. The vehicle also has a speed monitor with a gear ring positioned on an exterior surface of a stub shaft and a speed pickup positioned adjacent to the gear ring.

An all-terrain vehicle is disclosed having a braking system with an anti-lock braking control module and a first brake master cylinder hydraulically coupled to the anti-lock braking control module. A first brake actuator is coupled to the first brake master cylinder and a brake caliper is coupled to at least some of the ground engaging members. The first brake master cylinder upon actuation provides anti-lock braking to either the first or second ground engaging members. A second brake master cylinder is hydraulically coupled to the anti-lock braking control module. A second brake actuator is coupled to the second brake master cylinder and a brake caliper is coupled to at least some of the ground engaging members. The second brake master cylinder upon actuation provides anti-lock braking to either the first or second ground engaging members. The vehicle also has a speed monitor with a gear ring positioned on an exterior surface of a stub shaft and a speed pickup positioned adjacent to the gear ring.