Pressure pulse generator comprising - a cylinder - a first channel extending from the cylinder to a pressure sink LP - a second channel extending to the cylinder from a pressure source HP - a controllable first valve body arranged in the channel to open or close a pressure fluid flow in the channel - an electro element to control the valve body - an actuator piston being displaceably arranged in the cylinder - a spring applied in the cylinder to use its spring action to keep the actuator piston in its home position and to return the actuator piston to the home position after having left the same - a second valve body rigidly connected to the actuator piston and arranged at or in the channel for opening or closing of said second channel, characterized in that when activating the electro element the first valve body will displace from a starting position keeping the first channel open and the second channel closed to a position where it keeps the first channel closed and the second channel open at the same time as the second valve body keeps the channel open wherein a pressure pulse of pressure fluid from the pressure source HP is generated bringing the actuator piston with adherent second valve body to displace from the home position towards the remote position and that during said displacement of the second valve body the second channel will close and thus having the pressure pulse to terminate and that the first valve body keeps the first channel closed for evacuation of pressure fluid out of the cylinder until the electro element is deactivated and the first valve body returns to its starting position. - a cylinder - a first channel extending from the cylinder to a pressure sink LP - a second channel extending to the cylinder from a pressure source HP - a controllable first valve body arranged in the channel to open or close a pressure fluid flow in the channel - an electro element to control the valve body - an actuator piston being displaceably arranged in the cylinder - a spring applied in the cylinder to use its spring action to keep the actuator piston in its home position and to return the actuator piston to the home position after having left the same - a second valve body rigidly connected to the actuator piston and arranged at or in the channel for opening or closing of said second channel, characterized in that when activating the electro element the first valve body will displace from a starting position keeping the first channel open and the second channel closed to a position where it keeps the first channel closed and the second channel open at the same time as the second valve body keeps the channel open wherein a pressure pulse of pressure fluid from the pressure source HP is generated bringing the actuator piston with adherent second valve body to displace from the home position towards the remote position and that during said displacement of the second valve body the second channel will close and thus having the pressure pulse to terminate and that the first valve body keeps the first channel closed for evacuation of pressure fluid out of the cylinder until the electro element is deactivated and the first valve body returns to its starting position.