An electromechanical actuator for use in a hydraulic braking circuit of a vehicle comprises an electric motor having a stator and a rotor, and a linear actuator that is located within the motor. The linear actuator comprises an elongate shaft having a screw part at one end carrying an external thread that extends along a portion of the shaft, and a fixing part at the other end shaft, the linear actuator further comprising a drive nut that surrounds the screw part of the shaft and is located at least in a retracted position inside an enlarged bore of the first portion of the rotor body, the drive nut being connected to the screw part through a set of balls that engage the threads of the drive nut and screw part, and the fixing part of the shaft includes a tapering portion that engages a complimentary tapering portion of the bore in the second portion of the rotor body.

In the case of a method for operating a brake system in a vehicle, preferably a service brake system, in particular in a motor vehicle, it is first established whether the vehicle is stationary. If it is established that the vehicle is stationary, it is thereafter detected that the actuating member is actuated by the driver in order to leave the vehicle in the stationary condition. If it is established that the actuating member is actuated while the vehicle is stationary, a signal is generated at least to initiate the temporary under-supply of service brake medium to the operating members.