Air brake actuator assembly

The assembly (10) has a portion of cast iron brake housing (12) cast around another portion of a cylindrical steel air chamber (14). The chamber has a front shell and a rear shell that are joined together at a crimping point. The rear shell closes an open end of the front shell. The front shell is secured to the housing by a radially inwardly directed flange of the front shell that is mounted into the housing during casting. An independent claim is also included for a method of manufacturing a brake assembly.