An in-line brake system with a hydraulic booster includes a master cylinder defining a cylinder bore, a master cylinder piston located within the cylinder bore, a transfer piston located within the cylinder bore rearwardly of the master cylinder piston, a transfer piston actuator with a first seat, a sealing member aligned with the first seat, a sealing member spring operably connected to the sealing member and the transfer piston, an input rod aligned with the first seat, a return spring operably connected to the input rod and the transfer piston actuator, a sleeve actuator located within the cylinder bore rearwardly of the master cylinder, and a sleeve spring configured to bias the sleeve actuator away from the master cylinder piston, wherein the sleeve actuator is configured to bias the transfer piston toward the master cylinder piston in response to an applied boost pressure.