Power steering, also known as power assisted steering, makes steering a motor vehicle easier for the driver by reducing the amount of force that is required to be applied to the steering wheel when trying to manoeuvre the car and almost every vehicle that is built nowadays has some form of power steering system.
Although electric power assisted steering is rising in popularity, by far the most prevalent system at present is hydraulic power.
Hydraulic steering employs a pump, which is normally driven by a belt. The pump generates pressure and the driver’s control is provided by either a rack and pinion or a power steering box. Whichever of the two systems is used, the basic operation is the same. The fluid pressure generated by the pump is used to push against a piston. When the steering wheel is turned, pressure flows to one side, causing the piston, which is attached to the steering gears, to move. The driver is thereby able to allow hydraulic pressure to do most of the work involved in turning the steering wheel.
Although the rack and pinion system is felt to provide lighter weight and greater control precision, the power steering box is considered to be harder wearing and possess greater durability.