If you find it hard to turn your wheel, it could be possible that your car needs a new power steering pump. Replacement power steering pumps and other parts are available for all makes and models of car.
A power steering pump is usually found in the engine bay. It uses hydraulic power and is driven by the car's engine using a belt and pulley system. This pushes fluid into retractable vanes in the steering box, which in turn help to keep your steering nice and light.
Every time you turn the wheel, the vanes open up and let in fluid at high pressure to one side, which makes steering much easier. So, while you control the direction in which you drive, the power steering pump does most of the hard work for you. As in the case of any hydraulic system, the pump is vital to the efficiency of your power steering.