Power Steering and How it Works

It’s easy to take modern conveniences for granted. One example is a feature on our vehicles that makes our lives easier: poweer steering.

Once upon a time, you had to turn the steering wheel of a car to steer it much like turning the rudder of a ship struggling with large waves. Today, driving is much easier, as long as your power steering system is in excellent condition.

What is Power Steering?

Power steering is a vehicle component created for the purpose of maneuvering a car with the minimum effort necessary. In other words, it is what makes turning the steering wheel easy, without having to exert force, even at low speeds.

Before its creation in 1951, driving a car depended solely on the force exerted by the driver, so turning the car was difficult and sometimes lacked precision.

Types of power steering

Currently, there are three types: hydraulic, electrohydraulic and electric. Hydraulic is the most complex of the three, which is why many manufacturers have dispensed with it. In modern vehicles there is only electronic steering.

What are the components of a power steering system?

First, there are two main types of power steering: hydraulic and electronic. The latter is the most advanced in terms of technology and the one we see today in new cars.

Now, each one has its own elements that compose it, we are going to divide them by each type to make it clearer.

Hydraulic power steering elements

• Steering mechanism: Rack and pinion assembly or steering box, depending on the vehicle. This part is responsible for sending the steering signal from the axle to the steering rod, also making use of steering stubs.
• Steering pump: this element performs the function of pressurizing and sending the steering fluid to the entire mechanism, allowing a more fluid process and greater ease in turning the vehicle.
• Bypass valve: it maintains a constant steering fluid pressure.
• Fluid reservoir: We mentioned that the steering fluid helps by applying force to the mechanism, but it requires a reservoir where it is stored and gradually released as it is used.
• Hoses or conduits: it is through these that the pressurized steering fluid flows and returns to the reservoir.

Elements of electric power steering

• Steering mechanism: rack and pinion assembly.
• Electric steering motor: as is to be expected, this motor is the central piece that is responsible for applying the necessary force to turn the steering.
• Control module: it is the computer that operates the motor, it receives the information from the sensors.
• Sensors: angle sensor located on the steering wheel; a couple more sensors installed in the module and one more sensor that indicates the position of the engine to the EPS module.

How does the power steering work?

All power steering systems are activated only when the steering wheel is turned. Regardless of the type, it is required to move the steering wheel for them to work. Let's see how each type of steering works.

Hydraulic power steering, how does it work?

Hydraulic steering requires high steering fluid pressure, which originates from a pump that is driven by a belt linked to the trolley motor. Once the fluid is pressurized, it exerts the necessary force to turn the wheels. At higher engine revolutions, a higher pressure is exerted, although as there is a bypass valve, this high pressure is maintained or generated even at low revolutions.

How does electric power steering work?

In this type of steering, it is not necessary for the car's engine to work for it to be activated. This mechanism depends on its own engine and computer, the latter receives the signals from the sensors and sends the signal to the engine to move the direction of the wheels.

Common problems in power steering systems

As they have different components and ways of working, failures and problems will also differ from one type to another. Let's see the most recurrent problems of each one.

Failures in the hydraulic steering system:

• Leaks usually occur due to wear of parts such as hoses, gaskets or seals. This failure is easy to detect, when you see a dark spot under the car and a low level in the reservoir.
• Cracks in the fluid reservoir, even if you refill it with more fluid, if it is broken it will not last long before you throw it away again.
• The pump starts to fail, it may make noises and/or overheat. This will result in loss of assistance.

Failures in electric steering:

• Motor problems, mainly due to overheating or leaking water, dust or carbonized debris.
• Control module failures also due to excessive heat or dirt that has leaked into it.
• Poor reading of the contact torque sensors.

Hydraulic Power Steering (HPS) vs. Electric Power Steering (EPS)

Although the use of electric steering is becoming more and more common, there are still many car models that remain with hydraulic steering. Given this, we share with you a comparison between both types.

Here is a basic comparison table:

Power Steering Service and Maintenance Tips

It is important to understand that this element of the vehicle requires constant supervision, it is usually a bit delicate unlike other components. Among the basic maintenance points, we recommend:

• Check the steering fluid level, as well as the reservoir for cracks. In addition, check the condition of the steering fluid, that it is not dirty or of a color very different from what it usually looks like when it is new.
• Inspect connections for leaks, especially hoses and joints related to the steering.
• In the electric power-assisted system, make sure that the car battery is in good condition.
• Verify that there is no warning light on the dashboard indicating problems with the electric power steering.

In terms of maintenance, we can recommend that:

• Always use the steering fluid indicated by the car manufacturer.
• Avoid sudden maneuvers that may overload the system.
• Align the tires regularly or when required, this will extend the life of the steering system.

How often should we check the power steering fluid level?

This will depend on the vehicle model you have, but as a general rule we can say that at least once a month this inspection should be performed. Even earlier if we suspect that there is a low level of steering fluid.

When should I go to a specialist mechanic for power steering problems?

As with any failure of our car, when we see or hear something out of the ordinary, we should go to the workshop as soon as possible, but as for the power steering we suggest you go when:

• When turning the steering wheel, abnormal noises or squeaks are perceived.
• steering wheel hard to maneuver
• You detected fluid leakage when you saw the stain on the floor, but you do not know specifically where it is coming from.

Types of power steering fluid

We find different types of steering fluids, each one with specifications of use and performance according to the type. To find out which one your car needs, check the manufacturer's manual or, if you don't have it, ask an expert mechanic.

• Automatic transmission fluid (ATF): In some power steering systems, the same fluid used in automatic transmissions can be used. Check before use.
• Synthetic fluid: On newer models, it is necessary to use chemically generated synthetic fluid.
• Generic or universal power steering fluid.

Evolution and advances in power steering

Advances in power steering continue to this day. Technologies now exist that help vehicles adapt to wind shear (wind-assisted) and stay in lanes (lane-assisted). Power steering is also used in the automated parking systems found in modern high-end automobiles.

It's all part of the advances being made as the automotive industry develops more technologies and implements tools driven by artificial intelligence.

Stay away from power steering problems!

Take your car to a specialized mechanic and use the highest quality power steering parts.
At the SUN Transmissions online store, you will find a wide variety of products that you can purchase and have delivered to your doorstep, including transmission filter kit, sensors, coolers, automatic transmission solenoids, and the best transmission additives.
We have many options for rack and pinion kits, steering pump, power assist modules and the fluids you need, shop today!