Hydraulic power steering system, description and function

The power steering pump is a belt driven wing pump that produces hydraulic pressure and flow to the steering gear, which is of the rack type.

A pressure hose from the power steering pump supplies the steering gear with power steering fluid.

The power steering return hose returns fluid from the power steering gear back to the fluid reservoir. An integral fin-type or line-type power steering fluid cooler may be fitted on the power steering return line.

The steering gear's valve unit controls the incoming fluid to the right respectively left chamber to give the required power assistance.

Turning the steering wheel activates the valve assembly, which applies greater fluid pressure and flow to one side of the steering gear piston, and lower pressure and flow to the other side of the piston. The pressure assists the movement of the gear piston. Tie rods transfer this force to the front wheels, which turn the vehicle right or left.