Hydraulic Power steering.

It uses the force of pressurised liquid, continuously supplied by the power steering pump to assist the driver with steering. The pump is powered by the engine and normally driven by a belt component. It is connected to a cylinder which applies force to the steering gear, turning the car wheels. The system’s valves are operated by the steering wheel; the more pressure the driver applies, the more power steering fluid flows through the valves to the cylinder, generating a stronger force. The speed of the engine will also affect the amount of pressure generated by the device.