A braking system of a trailer and work machine includes a pressurized fluid supply, a hydraulic base valve fluidly coupled to the supply, and a pneumatic base valve fluidly coupled to the supply. A proportional control valve is also fluidly coupled to the supply, and it includes an outlet disposed in fluid communication with the inlets of the hydraulic base valve and the pneumatic base valve. The system further includes a hydraulic output configured to be fluidly coupled to a hydraulic braking system of a trailer, and a pneumatic output configured to be fluidly coupled to a pneumatic braking system of a trailer. The hydraulic output is fluidly coupled to the outlet of the hydraulic base valve, and the pneumatic output is fluidly coupled to the outlet of the pneumatic base valve.