Master cylinder assembly

Abstract

A master cylinder assembly for simultaneously actuating the front and rear wheel brakes of a vehicle. The master cylinder assembly includes a housing having a bore therein with a first piston separated from a second piston by a first spring to establish a first pressurizing chamber while a second spring separates the second piston from the bottom of the bore to establish a second pressurizing chamber. The second piston has a first passage which connects the first pressurizing chamber to a reservoir in the housing and a second passage which connects the second pressurizing chamber to the reservoir. A guide on the second piston is located in a keyway in the housing to prevent the second piston from rotating. A first telescoping sleeve member located on the first piston is aligned with the first passage while a second telescoping member attached to the housing is aligned with the second passage. An operator input moves the first and second pistons and simultaneously interrupts the communication of fluid from the reservoir through the first and second passages by seating the second piston on the second telescoping member and the first telescoping member on the second piston. Thereafter, the fluid in the first and second chambers is pressurized to synchronize the actuation of the front and rear brakes.