(EN) In a brake actuator including a plurality of actuator housing portions, a diaphragm seal, partially delimiting a parking brake de- actuation chamber, is retained between adjacent actuator housing portions, and an elastic element disposed between the diaphragm seal and one of the housing portions opposes expansion of the parking brake de-actuation chamber. Upon depressurization of the parking brake de- actuation chamber, a push rod extending through the parking brake de-actuation chamber produces brake actuation. The push rod extends into and out of a service brake actuation chamber upon respective release of fluid pressure from the parking brake de actuation chamber and supply of fluid pressure to the parking brake de-actuation chamber, and a piston, which is secured to and movable together with both the push rod and the diaphragm seal, acts as a seat for the elastic element.
