Step 1 - The power steering system utilizes hydraulic fluid to transfer force from the power steering pump to the rack and pinion or steering box. Check the power steering fluid level by locating the power steering fluid reservoir and remove the cap (twist counter clockwise) to inspect the fluid level in the pump fluid reservoir. Some systems have a fluid level dip stick mounted inside the cap while others are present on the side of the fluid reservoir, if the fluid level is down or empty the system has a leak. Inspect the pump, hoses and rack and pinion or box assembly, replace worn or broken components as needed.
Step 2 - The steering pump is driven by a serpentine belt which is used to transfer energy from the engine to the hydraulic steering pump assembly. If the belt is in poor condition or has failed completely it will render the system non-operational.
Step 3 - A hydraulic pump is used to supply fluid pressure which is needed to operate the system. If the pump fails internally, the pressure needed to operate the system is not present rendering the system non-operational. The power steering pump must be replaced and refilled with fluid. (Note: some power steering pump pulleys are pressed on and require a specialized tool to be removed and replaced).
Step 4 - If everything checks out and power steering problems still exist the rack and pinion, or steering box is the only component that remains. When replacing a pump be sure to flush the system before refilling it with new fluid.
A power steering system is designed to utilize power from the engine to assist in the force needed to steer the vehicle. A pump pressurizes the fluid and transfers it through hoses which are connected to a power steering box or rack and pinion. If the power steering malfunctions the vehicle can be difficult to control. It is advised NOT to move a vehicle with the power steering system not operating or engine not running.
Please if you are not a professional, please don't try this on your car so that you won't cause more damages to it