The power steering system is one of the most critical parts of any car, as it's this system that ultimately allows drivers to turn the wheel easily. When there's a problem with the power steering, the driver may find that they aren't able to control the vehicle. Sometimes this results in a complete steering lock-up, while other times the driver will have to use extra pressure to get the wheel to turn.
The first aspect of the system that needs checking is the power steering fluid. Drivers may be used to keeping tabs on many other liquids in their vehicle, such as oil, coolant and brake fluid. The difference with power steering fluid is that it typically doesn't need to be replaced all that often. Low levels of power steering fluid may indicate a leak or a problem with the power steering pump. However, older cars may naturally lose some power steering fluid, in which case fixing the issue is simply a matter of buying the fluid and topping off the reservoir levels.
In all likelihood, the problem will be more complex than that - especially if you're having trouble actually turning the vehicle. Open up the engine compartment and have a friend turn the steering wheel back and forth, with the engine on.
When this happens, it's very common to hear a whine or similar noise coming from the power steering pump. Drivers may also hear the noise during normal vehicle operation. This can indicate a number of different issues. The whining may be due to low fluid levels, as previously indicated. If you've refilled the fluid already and the hoses show no signs of leaking, then you may want to move on to the steering pump belt.
The steering pump belt will likely not simply snap off all at once. It may instead be subject to certain conditions. For example, sometimes the belt will be fine at low RPMs but begin to slip when the car gets up to speed. In other cases, the belt may only start slipping in the rain, or when the car is turned in a certain direction.
Fortunately, the belt can be adjusted by hand once the driver sees this is the problem. Obviously, be sure the engine is completely off before handling any moving part of the vehicle, especially a high-speed belt. Manually adjust the belt to ensure it doesn't slip off. If you don't feel comfortable doing this, a trained mechanic can do it for you.
If the fluid and belt both look good, the next step is to raise the front of the vehicle using a car jack and stands. Then, locate the steering assembly itself by using the owner's manual. Again, having a friend with you to help turn the wheel can be beneficial as you look at this part of the car. The most common issues with the steering assembly are loose or worn parts, which are usually somewhat easy to spot due to the noise they'll make when turning the wheel. Inspect the parts by hand to ensure they're all attached firmly to the vehicle.
In cars with rack and pinion steering systems, you should also check the seals. Even if you found no leaks in the hoses connected to the power steering pump, these seals could be the culprit when it comes to low power steering fluid.
Once all of these possible issues have been eliminated, it's probably best to take the car to a professional. Steering problems can get quite complex, and if it's not one of these common problems, you'll likely need an expert to help troubleshoot the issue.