FOUR-WHEEL disc brakes (ventilated front and solid rear) are standard on MX-5, measuring 20x255mm at the front and 9x251mm at the rear. An eight-inch vacuum servo assists braking. Dual hydraulic circuits are split front and rear, with the rear being pressure-modulated by a proportioning valve in order to prevent premature locking of the rear wheels. An anti-lock braking system is unavailable.