An electric booster and master brake cylinder assembly includes a master cylinder housing, a booster housing, a primary piston, and a ball screw assembly. The master cylinder housing defines a piston bore. The booster housing is attached to the master cylinder housing and defines a bore. The primary piston is slidably positioned within the piston bore and has an axially extending end portion that extends into the bore. The ball screw assembly is at least partially disposed within the bore of the booster housing.