Valve assembly for a trailer braking assembly

The assembly (7) e.g. modular valve unit (9), has a supply port (15) and a spring-loaded port (28), where an emergency braking- and/or uncoupling function is integrated in the assembly and causes automatic aeration of the spring-loaded port when the supply port is not under pressure. A valve body (3) is actuated by a manual actuating element (38) e.g. pivot lever, when the supply port is not under pressure and pressurized, for pressurizing and aerating the spring-loaded port in two valve positions, respectively. An independent claim is also included for a pneumatic trailer brake assembly.