A hydraulic system and method for controlling the brake of a wind turbine are provided. During operation of the wind turbine, pressurized working fluid in the hydraulic system is blocked from being supplied to the brake. Even if some of this fluid does reach the brake, it is drained to prevent a pressure build-up and activation. To activate the brake, this drainage is stopped and the pressurized fluid is supplied to the brake. The blocking and unblocking the pressurized working fluid may be controlled by first and second activation valves arranged in parallel in a supply line that communicates the working fluid to the brake.