A power steering system helps drivers steer the vehicle by augmenting steering effort needed to turn the steering wheel, making it easier for the vehicle to turn or maneuver. Hydraulic or electric actuators add controlled energy to the steering mechanism, so the driver can provide less effort to turn the steered wheels when driving at typical speeds and reduce considerably the physical effort necessary to turn the wheels when a vehicle is stopped or moving slowly.Power steering can also be engineered to provide some artificial feedback of forces acting on the steered wheels. The hydraulic power for the steering is provided by the power steering pump). This pump is driven by the car's engine via a belt and pulley. It contains a set of retractable vanes that spin inside an oval chamber. As the vanes spin, they pull hydraulic fluid from the return line at low pressure and force it into the outlet at high pressure.The amount of flow provided by the pump depends on the car's engine speed. The pump must be designed to provide adequate flow when the engine is idling. Main symptoms of a failing power steering pump is a stiff steering wheel and whining noise while turning the wheel.