Power Steering: Operation

The steering column shaft is attached to the gear pinion. The rotation of the pinion moves the gear rack from side-to-side. This lateral action of the rack pushes and pulls the tie rods to change the direction of the front wheels. 

Power assist is provided by an engine mounted hydraulic pump, the pump supplies hydraulic fluid pressure to the steering gear. Some vehicles are equipped with an oil cooler mounted in front of the radiator.