FAILURE DETECTION DEVICE OF HYDRAULIC BRAKING DEVICE

PROBLEM TO BE SOLVED: To provide a failure detection device of a hydraulic braking device which can detect a failure in X piping without using a hydraulic pressure detection sensor.SOLUTION: A failure detection device of a hydraulic braking device 10 with hydraulic piping including a first piping system 12 for feeding hydraulic fluid to a wheel cylinder of a left front wheel and a wheel cylinder of a right rear wheel to generate braking force and a second piping system 14 for feeding hydraulic fluid to a wheel cylinder of a right front wheel and a wheel cylinder of a left rear wheel to generate braking force, includes: a stroke sensor 18 for detecting magnitude of braking demand; a steering angle sensor 44 for detecting a variation amount of a steering angle between before and after generation of braking force when the braking force is generated in response to the braking demand; and a failure detection unit 100 for detecting an occurrence of failure in either the first piping system or the second piping system when the variation amount of the steering angle relative to the magnitude of the braking demand is larger than a predetermined value.