Electric Power Steering Fluid

Electric Power Steering Fluid: A specialized synthetic power steering fluid designed for use in “electro-hydraulic” power steering systems that use an electric motor instead of a traditional belt-driven pump to provide hydraulic pressure.


  • Reduces friction and heat that can wear out the pump, valves and gears.
  • Extends system life by reducing wear on internal components.
  • Reduces squeals and vibrations due to foaming.
  • Excellent performance in cold climates.


How can you effortlessly maneuver thousands of pounds of steel just by turning a handwheel? 

Modern power steering emerged in 1951 with the introduction of the Chrysler Imperial, which used hydraulic power to make driving easier. Today many cars have switched to electric power steering. 

But what is the difference between electric and hydraulic power steering? Read on to learn the pros and cons of electric power steering versus hydraulic power steering and how to troubleshoot potential problems with your system.


In simple terms, power steering reduces the effort required to turn a vehicle’s steering wheel. Without the electrical or hydraulic assistance of the power steering system, the steering wheel would feel heavy and difficult to turn. If you’ve ever had your vehicle’s power steering turned off, you know that cornering, parking, and maneuvering your car, especially at low speeds, suddenly becomes a complete upper-body workout.


There are three types of power steering in today’s vehicles: electric, hydraulic, and a hybrid hydroelectric system. Next, we will discuss the difference between electric power steering and hydraulic power steering.

An all-electric power steering (EPS) system uses an electric motor, mounted on the steering rack or steering column, to assist the driver. Sensors attached to the engine measure how much torque, or rotational effort, the driver is applying to the steering wheel. The sensors then use that information to decide how much assistance the driver needs to turn the front wheels. 

Speed ​​is the most important factor in determining how much assistance the EPS provides. You may notice that the steering wheel is very easy to turn at low speeds, such as when parking, to make maneuvering easier. At higher speeds, greater flywheel resistance provides greater stability.

However, hydraulic systems use hydraulic fluid powered by a power steering pump to help drivers turn the steering wheel. While an EPS is powered by the car’s 12 volt (or higher) electrical system, the power steering pump is driven by the serpentine belt or other drive belt connected to the engine. The power steering pump uses power steering fluid to create hydraulic pressure in the steering gear or pinion gear that the driver must move to turn the wheels. 


Hydraulic power steering has been the dominant power steering system for over 50 years. Because of this tenure, it has benefited from decades of development and fine-tuning. Proponents of the hydraulic assist method single out one big advantage – the ability to feel the road through the steering wheel. 

More feedback from the road, or steering feel, creates a smoother driving experience because the driver can better understand how the car is handling. In a way, the road communicates with the driver through the steering wheel, allowing for more intuitive decision making and overall safer driving. For this reason, many drivers of high-end sports cars and race cars prefer hydraulic assistance. It allows them to make faster and more informed decisions while driving at high speeds.


Despite having been used for so long, hydraulic power steering has some disadvantages. First, hydraulic power requires the use of hydraulic fluid, also known as power steering fluid. Although some vehicle manufacturers do not require it, power steering fluid can be replaced on a regular basis, approximately every five years or 50,000 miles. Also, if this fluid leaks below a certain threshold at any point, you may lose power steering assist.

Second, the power assist is “always on,” which means the engine has to constantly work for the power steering assist to work. Systems that require the mechanical power of the engine to function can affect fuel efficiency and gas mileage.

Lastly, hydraulic power steering systems are more complex and require more parts than an electric power steering system. In this way, they can take up more space in the engine compartment.


Since the early 2000s, electric power steering has become the standard for most cars. This is mainly because an EPS system is generally simpler and easier to maintain than its hydraulic counterpart. Electric systems do not require power steering fluid to function and only consume power when needed, making them more fuel efficient than hydraulic systems.

Plus, EPS enables the modern driver assistance features we rely on, like auto park and lane keeping assist. It will also be essential as we move into the future of autonomous cars.

Compared to hydraulic power steering, EPS better compensates for wheel misalignment and steering-affecting driving conditions, such as high winds and uneven surfaces. And since the system is fully electronic, it’s easier to fine-tune the precision of the power assist through simple software updates.


Although electric power steering systems are now standard, they still have a couple of drawbacks. Unlike traditional hydraulic systems, previous EPS systems initially lacked the steering feel, or feedback, from the road that helped inform drivers about how their car was handling. These days, manufacturers have largely corrected this problem, making the feel of electric vs. hydraulic power steering almost indistinguishable.

Another downside to electric power steering is that it cannot be easily serviced with standard parts and labor like a hydraulic system. EPS systems may require specialized equipment and knowledge to diagnose and repair electrical problems that may be caused by a faulty on-board computer or various sensors. As a result, repairs to electric power steering units often cost more than hydraulic units.


Since the driver’s hands are always on the wheel, power steering problems often come to his attention quickly. If you notice any of the following symptoms, you may have a faulty power steering system or low power steering fluid:

Poor vehicle response when turning Hissing or growling when turning. This can also indicate low fluid levels.

A stiff steering wheel that requires more effort than normal to turn

What is electric power steering?

Turning the steering wheel of a car or truck is easy with hydraulic or electric power steering. It can be done with one finger. But that wasn’t always the case, especially at low speeds like parking or turning. In the first half century of the automotive industry, a lot of force was required to turn the wheel of a stationary or slowly moving vehicle because it was literally a matter of moving the wheels under the weight of the vehicle.

In 1951, all that changed. The Chrysler Imperial was introduced with power steering and was so popular that it quickly became popular with other car manufacturers. The timing was perfect, as the postwar move to the suburbs and the increase in female drivers skyrocketed demand for automobiles in general, and in particular for those that offered comfort and utility.

The popularity of power steering had the obvious benefit of making it easier to turn the steering wheel, but it also allowed engineers to increase the turn ratio, that is, the amount of spin of the front wheels with each revolution of the steering wheel. Whereas it used to take many turns of the steering wheel to change a vehicle’s direction, power steering allowed them to lean much more with each turn. Particularly when parking and turning, this significantly facilitated the operation of the vehicle. Today, people take for granted how little effort it takes to turn a vehicle over 2,000 pounds.

Power steering was the first power

steering The first power steering involved power steering, which worked with hydraulic fluid pumped under high pressure. Those systems prevailed in the automotive world for another half century until the early 2000s. Hydraulic steering gave drivers a real sense of control over vehicle movement and provided most of the power needed to change the direction of the vehicle. vehicle. From a steering perspective, power steering was a great system.

Hydraulic steering had its drawbacks, most notably its inefficiency. Because the pump is driven by the engine and must run constantly, even when the vehicle is idling or moving in a straight line, it consumes power and fuel consumption. Experts say power steering costs five to eight horsepower and gets one to three miles for every gallon of gas. In a vehicle that travels an average number of miles per year and achieves average gas mileage at normal gas prices, that’s a cost of about $200 per year. Wind resistance and road friction alone cause more drag on a car than the hydraulic power steering system.

Also, hydraulic fluid must be replaced periodically and can leak from the hydraulic fluid lines that carry it to and from the pump. When fluid levels drop, it becomes more difficult to turn and assistance may be lost until the leak is repaired and the fluid replaced.

How Electric Power Works

Car manufacturers began looking for a more cost-effective method of power steering in the 1980s, along with the computerization of vehicles. By 1993, Honda had advanced enough on its electric power steering system to introduce it to its luxury Acura line. It immediately gained traction among manufacturers and the car and truck buying public. Today it is the norm in new cars and trucks.

In an electric power steering system, an electric motor attached to the steering rack or the steering column itself turns the wheels based on the driver’s actions. The engine is guided by sophisticated electronic circuitry that is now standard in most on-board computer systems.

Electric vs. Hydraulic Steering

Electric steering has several advantages over hydraulic steering. The first is that the steering motor works with the vehicle’s electrical system without draining power from the motor. There’s no loss of power or fuel efficiency, giving models with electric power steering an immediate competitive edge. It also eliminated the need for a bulky hydraulic pump, power steering fluid, and leaking hydraulic fluid lines.

Another advantage of electric power steering is the high-tech assistance computers that they can offer to the driver. Sensors have been added to detect vehicle speed and driver effort to measure the amount of assistance required with each turn of the steering wheel. When parking or performing a three-point turn, the power steering is stepped up to lighten the load on the driver trying to negotiate difficult angles and distances.

At highway speeds, the power steering backs off, giving the driver a sense of control behind the wheel. This also provides greater stability, since an overly responsive steering system at 60 miles per hour could cause the vehicle to roll all over the road.

Even more than that, electric steering systems are now so computerized that they automatically adjust based on the subtlest of road conditions. For example, they take into account the crown of the road (which allows water to drain from the center line onto the shoulders), wind conditions, and misaligned wheels when determining how far to steer the vehicle. Drivers are hardly required to drive today.

That’s a big step toward the autonomous vehicles of tomorrow, which will be guided by on-board computers incompatible with a hydraulic steering system.

If the power steering is leaking

Most vehicles made before 2015, and many made after, use a hydraulic or hydraulic-electric hybrid power steering system, which are prone to fluid leaks that can deplete power steering power . To stop the leak and seal it permanently, use a sealant like BlueDevil Power Steering Stop Leak.

BlueDevil Power Steering Stop Leak’s pour-and-use formula repairs rack and pinion systems as well as fluid lines in domestic, import and commercial grade power steering systems.

With the engine off, simply pour a third of the bottle into the power steering reservoir, start the engine, and drive it for an hour or two until the leak stops. If the leak persists, continue adding the sealant until it stops.

As it circulates throughout the power steering system, the product revitalizes hard, shrunken seals and extends their life, returning steering control to the driver.

What Causes Electric Power Steering Failure?

This type of steering is not without its problems, just like any electronic or mechanical system. While there are no electric power steering pumps, fluids or fluid lines, there is an electric motor and the power steering control module – the computer that receives information about vehicle speed, steering position and torque, to instruct the motor and produce steering feedback to the driver.

These two parts do the landlord job for hundreds of thousands of miles, usually without complaint. However, anyone who has ever operated a computer knows that it can crash suddenly for no apparent reason, often giving an error code that doesn’t exactly explain anything. In the case of a steering system, the failure of the computer that guides the system causes a failure of the power steering itself, leaving the driver to steer the vehicle entirely with muscle power. Specific problems affecting the control module include a failure in data exchange between the steering system and other modules in the system, and problems with the feedback portion of the system.

The other main culprit for electric power steering failure is the motor. Engines malfunction in various ways and for various reasons. They can flood or rust, or suffer jostling damage from driving at high speeds over bumpy roads. Something as simple as a fuse that sends electricity to the motor can blow. Parts inside the motor can wear out, especially the brushes and other moving parts. When the engine fails, the power steering stops.

How to Repair

Electric Power Steering Although electric power steering can fail suddenly, more often than not, it dies a slow death. It is possible to diagnose the problem before it is a total loss.

The most obvious indicator that the power steering is not working properly is the indicator on the dash. However, the EPS warning light usually doesn’t reveal a problem until it becomes terminal, so it’s wise to pay attention to other indicators that your power steering should be checked:

  • The steering wheel feels heavy and unresponsive
  • The steering wheel is stiff and hard to turn
  • Vehicle screeches when starting (this can be a symptom of many issues other than power steering)
  • Vehicle makes a high pitched whine when steering wheel is turned.

When it comes to repairing your electric power steering, the first step is to determine if the problem is with the motor or with the computer module. If the engine does not appear to be the culprit, the vehicle will need to be taken to a service station that can link the system to a computer in order to diagnose the exact problem.

For motor problems or problems with any of the connections between the motor and the flywheel, a simple DIY replacement is possible.

The cost to repair electric power steering is significant. Most dealerships and repair shops will simply replace the entire steering column for anywhere from $600 to $1,500. Replacing the module itself costs between $900 and $1000, mostly in the form of labor.
If you find this post about Electric Power Steering Fluid helpful to you and you want to know more about car fluid knowledge, please check more on our website Auto Oil And Fluid. Thank you for your interest!



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