Power Steering Explained: How It Works & How to Care For Yours

What Is Power Steering?

The power steering system allows us to easily turn our vehicles without needing to wrestle with the entire weight of the vehicle. This is commonly done through the use of hydraulic fluid; however, electric power steering systems have become increasingly popular in modern vehicles due to their compact design and superior reliability, as well as the ability to tie into other modern driving assists such as electronic stability and control (ESC) and active cruise control.

Hydraulic systems use a pump from the engine’s accessory belt to pressurize the power steering fluid, which, due to being incompressible, transfers and amplifies the force rather than absorbing it. Through this process, the power steering system makes the steering wheel much easier to turn with the use of hydraulic pressure.

Electric steering systems operate quite differently and refrain from hydraulics entirely, using a set of sensors and motors within the steering column to lessen the resistance of the steering wheel when turning.​

Steering wheel up close

What Components Make Up The Power Steering System?

While other vehicle makes may use different designs, most power steering systems rely on various key components working together to help turn your vehicle.

Steering Wheel and Steering Column

The steering wheel is directly connected to the steering column, which helps transfer the driver’s input to the steering system. When you turn the steering wheel, that motion travels through the column to the steering gear.

Steering Rack or Steering Gear

The steering rack converts the rotational motion of the steering wheel into the side-to-side movement that turns the vehicle’s wheels. Most modern vehicles use a rack-and-pinion steering system, which is compact and makes everything precise and efficient.

Power Steering Pump

In hydraulic systems, the power steering pump generates pressure that assists the steering movement. The pump is usually driven by the engine through a belt and continuously circulates power steering fluid through the system.

Power Steering Fluid

Power steering fluid acts as the hydraulic medium that transfers pressure within the system. It also helps lubricate components and prevents overheating.

Hoses and Valves

Hoses are used to transfer pressurized fluid between the pump and steering gear. Control valves regulate the direction and amount of pressure applied depending on how the driver turns the steering wheel.  

How Does Power Steering Work?

When you turn the steering wheel, it rotates the steering column, which is connected to the steering gear and ultimately to the wheels. As you do this, a control valve within the power steering system detects the direction and amount of force you’re applying. The power steering pump responds by sending pressurized fluid through hoses to the steering rack. Guided by the control valve, this fluid is directed to one side of the rack, depending on which way you’re turning.

This hydraulic pressure helps move the steering rack in the desired direction, significantly reducing the effort required to turn the wheels. When you straighten the steering wheel, the system redirects the hydraulic fluid and returns to its neutral state. This entire process happens automatically and continuously as you drive, ensuring smooth and easy steering.

Types of Power Steering Systems

Hydraulic Power Steering

Hydraulic (which simply means a liquid moving under pressure in a confined space) power steering uses a compressed fluid to assist the driver when they turn the wheel. The fluid is pressurized by the power steering pump, which runs off the engine.

A rotary valve controls the flow of the pressurized power steering fluid to one side of a hydraulic piston, depending on which way the wheel is turned. The hydraulic fluid assists in the turning of the wheels, meaning the input required from the driver is kept to a minimum.

Hydraulic power steering has been around for a long time. It’s a well-understood and engineered concept. If you ask an enthusiast, you may hear them say that hydraulic steering has a better “road feel”, or a more physical feeling connection to the road.  

Hydraulic steering is not without flaws, though. These systems are more complicated since they require the use of an engine-driven power steering pump. More components increase the likelihood of failures.

The hydraulic fluid pressurized by the pump can also become contaminated. On some vehicles, periodic fluid changes are needed. While the intervals between changes are usually much longer (50,000 miles or more), it’s still a maintenance item that electric power steering systems do not need.

Electric Power Steering

Electric power steering, or EPS, removes the power steering pump, fluid, and lines from the system. Instead, an electrical motor is fitted to the steering column and provides the boost needed to make steering easier. This type of steering system communicates with the ECU (engine control unit) using sensors, allowing the system to adjust steering based on vehicle speed and conditions.

Since electric power steering is not directly dependent on the engine (the motor gets power from the alternator only when the wheel is turned), it may contribute to better gas mileage. EPS systems are also less complicated than their hydraulic counterparts, which are less likely to have problems, and require less, if any, maintenance.

When EPS was first introduced, many drivers complained about a lack of steering feel or feedback. Early EPS systems disconnected from the road, often described as “numb”. The feedback from EPS systems has improved significantly since then. Companies like Porsche now include electric power steering in their high-end sports cars.

Signs Your Power Steering Needs Attention

  • Whining or groaning when turning
  • Stiff or heavy steering
  • Jerky or inconsistent assist
  • Squealing at startup (belt issues)
  • Visible fluid leaks (red, amber, or pink puddles)
  • Foamy or dark fluid
  • Steering warning light (especially on EPS cars)
  • Callout: when it’s safe to keep driving vs. when to stop

Common Causes of Power Steering Problems

Power Steering Pump

As the heart of your hydraulic steering system, you can imagine that issues with the power steering pump can cause significant issues in the system. Responsible for continually moving hydraulic fluid from the steering rack as needed, the pump will experience gradual wear from regular use and old age. Pumps can also fail due to factors such as weather exposure, old/insufficient fluid, or the failure of an internal component.

Symptoms of a failing power steering pump include a whining or whirring noise while turning, difficulty turning the wheel, or unusual sensations from the vehicle.

Fluid Leakage

As we discussed above, hydraulic power steering systems use incompressible fluid to transmit force. When this fluid exits the system due to a leak, there may be an insufficient amount to keep the hydraulics working, and it can leave your power steering pump struggling to keep up. If you notice red fluid under your vehicle when parked, you could be looking at power steering fluid, and should have your vehicle inspected by a trusted professional as soon as possible to avoid further damage.

Oftentimes, this will lead to a similar whining noise as a failing pump, as the lack of fluid causes the pump to work harder, or eventually fail. ​

Electric Power Steering

Electric power steering systems ditch the traditional hydraulic fluid for a drive-by-wire approach, instead relaying the movements of your steering wheel to an electric motor that controls the rotation of the steering rack.

Wiring Issues

As an electrical system, it’s no secret that corroded or damaged wiring is a potential failure point. Whether it be due to corrosion of the wires or external damage, any shorted or frayed wires can disrupt the operation of the entire power steering system. ​

Faulty Sensors

The sensors in an EPS system are what the motor relies on to control the rotation of the steering rack, meaning that even a single faulty sensor can lead to a host of issues when attempting to steer your vehicle.

This issue may present itself as jerky steering movements, a clicking noise when turning, and a stiff steering feel. Oftentimes, a failed sensor will be accompanied by a steering-system warning light on the dashboard.

How to Care For Your Power Steering

  • Check fluid regularly (how, where, when, what the fluid should look like)
  • Use the correct fluid type (check the owner’s manual; why mixing fluids is risky)
  • Schedule fluid flushes (typical intervals and why they matter)
  • Inspect belts, hoses, and connections.
  • Avoid holding the wheel at full lock.
  • Fix leaks early
  • Keep tires aligned and properly inflated (reduces steering strain)
  • Note on EPS: little fluid maintenance, but keep up with battery and electrical health and software updates.

Power Steering Service in Toledo, OH

No matter if your vehicle uses a hydraulic or electric power steering system, the experienced team at Toledo Auto Care has the training and equipment to provide you with the utmost quality of power steering system maintenance and repair.

Don’t let steering issues linger and potentially lead to dangerous circumstances and further damage; give us a call or schedule online to secure your appointment with Toledo’s premier power steering maintenance facility!

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