Electric over hydraulic brake system with magnetic sensor

A trailer braking system having a surge component used in combination with an electric over hydraulic brake system. The surge component includes a sliding member with a magnetic sensor for detecting trailer deceleration, the sliding member providing an initial pressurization of the hydraulic system. A trailer mounted electrical circuit detects when the tow vehicle brakes are applied and includes a microcontroller for detecting the speed of deceleration provided by the magnetic sensor. A trailer mounted electric motor receives a signal from the circuit board to vary pressure to the brakes in accordance with the speed of deceleration.