What is power steering?
Driving has never been easier than it is today, as modern steering and car suspension systems allow drivers to steer the car effortlessly, ensuring a smooth, safe car ride. This would not have been possible without the invention of power steering. It is a system which assists drivers by amplifying the torque applied to the steering wheel using a hydraulic or electronic device, thereby reducing the amount of effort needed to steer and maneuver the vehicle. Due to the sheer size and mass of most modern vehicles, without it, steering would be considered an intense strength training exercise.
Although power steering dates all the way back to 1876, the system was not commonly used in passenger cars until the 1950s. In 1951, Chrysler introduced its Imperial model, which was the first passenger car with power-assisted steering that was made available to consumers. Its “Hydraguide” system was a huge success and many manufacturers followed suit soon afterwards.
Types of power steering systems & how they work
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Hydraulic
The first systems that were introduced used a mechanical hydraulic device which is still used in some cars today. It uses the force of pressurised liquid, continuously supplied by the power steering pump to assist the driver with steering. The pump is powered by the engine and normally driven by a belt component. It is connected to a cylinder which applies force to the steering gear, turning the car wheels. The system’s valves are operated by the steering wheel; the more pressure the driver applies, the more power steering fluid flows through the valves to the cylinder, generating a stronger force. The speed of the engine will also affect the amount of pressure generated by the device. -
Electro-hydraulic
These hybrid systems are fairly rare but operate in a very similar way to hydraulic power steering systems (HPS). The main difference is that the hydraulic pump is driven by an electric motor, powered by the car battery.
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Electric
Electric power steering systems (EPS) are the more popular choice for car manufacturers nowadays. The EPS helps to steer the vehicle without the use of fluid. Instead, it uses an electric motor, a computer module and sensors. The sensors send data on the position of the steering column and the torque applied by the driver to the computer, and then the computer determines the amount of assistive force the motor needs to generate. The computer is usually able to adjust this based on the driving conditions and speed of the vehicle. The main advantages of an electric system are that it is able to respond more effectively when the wheels are misaligned, it doesn’t require regular maintenance, and less fuel is used.
Symptoms of a failing power steering system
- ! The steering wheel is stiff. If you have to use a lot of force to steer the car and feel your arms getting tired, it is highly likely that the power steering components are not working as they should be. This could be caused by mechanical damage or a fluid leak. However, steering difficulties can have a number of causes, such as bad wheel alignment or tyre pressure issues. It is important that the problem is properly diagnosed.
- ! A whining or squealing noise when steering. If you hear these noises when turning the steering wheel, you should get the system checked. It is often caused by a faulty pump or leak.
- ! Low fluid levels in the reservoir. If the steering fluid is unusually low, this could be due to a leak. A lack of fluid will negatively affect steering and could eventually cause the pump to fail.
- ! The steering wheel vibrates. For hydraulic systems, this usually occurs due to a problem with the drive belt, such as slipping or wear.
Maintenance tips
There are a few simple steps that you can take to make your power steering system last longer, however, these mostly apply to hydraulic and hybrid systems as electric ones are low-maintenance. Regardless of the type of system, the most important thing to do is react quickly to any steering issues, as they pose a risk to your safety and your car.
How to care for your steering system:- i Check the steering fluid level regularly to ensure that there is enough clean fluid.
- i Flush and change the fluid if necessary.
- i Inspect the hoses for cracks and damage.
- i Inspect the components for leaks.
- i Check the pump every so often and replace it immediately if there are signs of damage.
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