Store ejector rack systems and methods having an improved fluid actuator assembly for sequencing the opening of the hooks from which the store is suspended and the pressurization of thrusters which force the store away from the aircraft are disclosed. In one embodiment, an actuator assembly includes a staged valve assembly including a primary valve for controlling the flow of high pressure fluid from an accumulator to the thrusters, and a slave piston independently movable with respect to the primary valve for actuating the hook release mechanism.