What is a power steering wheel and how does it work?

Doesn’t matter if it’s a new or a used car part, a power steering wheel is an essential component of modern vehicles, a must-have car electronic that is designed to make steering much easier and more comfortable for drivers. Unlike traditional manual steering systems, power steering uses additional power to assist the driver in turning the wheel, reducing the effort required, especially at low speeds or when the vehicle is stationary.

This assistance can come from hydraulic, electric, or electro-hydraulic systems, each providing a unique method of support. Hydraulic systems use fluid pressure generated by a pump, electric systems rely on motors and sensors, and electro-hydraulic systems combine both technologies for enhanced efficiency and performance.

But do you know how it works and how to do the maintenance? Let’s get into it.

How Power Steering Works

Power steering systems are essential for modern vehicles, making steering easier and more comfortable for drivers. These systems can be categorized into three types: hydraulic, electric, and electro-hydraulic. Each type uses different mechanisms to assist with steering, reducing the physical effort required from the driver.

Hydraulic Power Steering (HPS)

Hydraulic power steering is the traditional form of power steering. Here’s how it works:

• Pump Mechanism: The system uses a pump, usually driven by the vehicle’s engine, to circulate hydraulic fluid under high pressure.
• Fluid Circulation: When the driver turns the steering wheel, valves within the system open and direct this pressurized fluid to a piston located in the steering gear.
• Assistance in Steering: The pressure of the hydraulic fluid helps move the piston. This movement assists in turning the vehicle’s wheels, making it easier for the driver to steer.

Hydraulic systems have been widely used for many years due to their reliability. However, they continuously draw power from the engine to run the pump, which can slightly reduce fuel efficiency.

Electric Power Steering (EPS)

Electric power steering represents a more modern approach. It operates differently from hydraulic systems:

• Electric Motor: Instead of hydraulic fluid, an electric motor provides the steering assistance.
• Sensors and Computer Control: Sensors detect the torque (rotational force) applied by the driver on the steering wheel. A computer processes this information and determines the amount of assistance needed.
• Precise Assistance: The electric motor then supplies the appropriate level of aid to the steering mechanism, ensuring smooth and precise steering.

EPS systems are becoming increasingly popular because they are more energy-efficient. They only use power when steering assistance is needed, improving fuel efficiency. Additionally, EPS allows for advanced features like variable assist levels, which can adjust the amount of steering help based on driving conditions, and integration with advanced driver-assistance systems (ADAS), enhancing safety and convenience.

Electro-Hydraulic Power Steering (EHPS)

Electro-hydraulic power steering combines elements from both hydraulic and electric systems:

• Hybrid Mechanism: This system uses an electric motor to drive the hydraulic pump.
• Efficient Power Use: By combining both technologies, EHPS provides reliable steering assistance while reducing the load on the vehicle’s engine.
• Balanced Benefits: EHPS systems offer the robust performance of hydraulic systems with the energy efficiency and advanced control capabilities of electric systems.

Advantages of Power Steering

1. Ease of Use: The primary benefit of power steering is that it makes steering much easier. Drivers don’t have to exert as much physical effort to turn the steering wheel, which is especially beneficial in tight parking situations or when making sharp turns.
2. Safety: Power steering improves vehicle control and handling. It allows for quicker and more precise responses to steering inputs, which can be critical in emergency situations.
3. Comfort: Reduced effort translates to a more comfortable driving experience, particularly on long trips. Drivers experience less fatigue, which can enhance focus and safety on the road.
4. Fuel Efficiency: Modern electric power steering systems are more fuel-efficient because they only use power when needed. In contrast, traditional hydraulic systems continuously draw power from the engine, reducing overall fuel economy.

Maintenance and Care

Like any vehicle component, power steering systems require regular maintenance to function properly and ensure longevity. For hydraulic power steering systems, this involves routine checks of the power steering fluid levels and the condition of the fluid itself. It’s essential to ensure there are no leaks in the system, as low fluid levels can lead to harder steering, increased wear on the power steering pump, and potential damage to the steering rack. Contaminated fluid can also cause blockages and reduce the efficiency of the system, leading to more significant problems over time.

On the other hand, electric power steering systems generally require less maintenance since they do not rely on hydraulic fluid. However, it is still crucial to inspect these systems regularly for any electrical issues, such as faulty sensors, loose connections, or problems with the electric motor. Sensor malfunctions can lead to improper steering assistance, making the vehicle harder to control and potentially compromising safety.

Regular maintenance and timely inspections help prevent minor issues from becoming major problems, ensuring the power steering system continues to operate smoothly and efficiently. Whether your vehicle has a hydraulic or electric power steering system, keeping it in good condition is vital for optimal performance, safety, and driving comfort.

Common Issues

Leaking Fluid

• Hydraulic systems rely on pressurized fluid to assist in steering.
• Fluid leaks can lead to a drop in fluid levels, decreasing steering performance.
• Common leak points include hoses, seals, and the power steering rack.
• Leaks can cause significant damage to the power steering pump or steering gear over time.
• Regular checks and prompt repairs are essential to maintain system integrity and functionality.

Noisy Steering

• Whining, squealing, or groaning noises when turning the steering wheel often indicate issues with the power steering pump.
• These sounds can be due to low fluid levels, possibly from a leak.
• In electric power steering systems, unusual noises could suggest problems with the electric motor or associated components.
• Early attention to these noises can prevent more severe damage and ensure smooth operation.

Steering Difficulty

• Heavy or stiff steering indicates serious issues in the power steering system.
• In hydraulic systems, this often points to a failing pump or significantly low fluid levels.
• In electric power steering (EPS) systems, it could result from electrical faults, such as failing sensors or motor issues.
• Steering difficulty compromises vehicle manoeuvrability and safety.
• Immediate inspection and repair are crucial to restore normal steering function and ensure safe driving conditions.

Conclusion

The power steering wheel has revolutionized the way we drive by making steering easier, enhancing vehicle safety, and providing a more comfortable driving experience. Understanding how it works and maintaining it properly can ensure that this crucial component continues to function effectively, contributing to a smoother and safer journey on the road.