For vehicles with EZGO (Easy Go: parking and gradient braking system that supplies positive braking when the vehicle is stationary on an up gradient and then facilitates moving off), the waterproofing mechanism of the solenoid valves for controlling is not appropriate, and therefore, water that contains snow-melting agent may enter inside the valves and cause rust. If this occurs, the hydraulic circuits may remain closed when the EZGO is activated, in which case the braking may continue, and in the worst case, the brake would overheat and catch fire.