What is power steering? Power steering is what allows you to maneuver a car with the force of a single finger. A steering wheel physically transfers the driver’s intention to turn the vehicle through a rack and pinion into the axle of the front wheels. But without any form of power steering, you must use muscle power or a gearing system to churn your front wheels around, especially at lower speeds. Power steering utilizes either hydraulics or electrical servos to translate input from the driver into leftwards or rightwards steering on the wheels.
Before the advent of power steering, in the 1950s and earlier, cars had to be manually turned around. This wasn’t that much of a chore when you were going 60 miles an hour on the highway, and just needed to change lanes. But when maneuvering into a parallel parking spot or taking a tight turn into an alley in the middle of a busy city at less than 20 miles an hour, turning your car around suddenly became a genuine physical challenge, depending on the sheer weight of the car and the breadth of the wheels – the wider the tires, the more traction they had, and the heavier they steered.
Engineers utilized a system of gears to make things a little easier – but this meant much, much slower steering because now the driver had to turn the steering wheel for far longer to get the car to fully rotate its wheels in either direction, especially while moving slowly or in a total standstill.
While the first power steering system was developed in the 1920s, it didn’t see widespread implementation until the Second World War, when British and American troops needed a better solution to deal with operating the beating heart of modern military logistics: the truck. Chrysler then produced and popularized the first mainstream power steering system in 1951, with the Chrysler Imperial. Other markets followed suit soon thereafter, especially in heavier cars with wider tires, where hydraulic assistance became a massive help.
How Does Power Steering Work?
Power steering is split between three main types: hydraulic power steering, electric power steering, and modern steer-by-wire technology.
Hydraulic and electric power steering share the most similarities. While both use different systems, the general explanation is the same – the driver’s input is amplified through the power steering system to turn the wheels of the car in tandem with the steering wheel.
Hydraulic Power Steering
Hydraulic power steering utilizes a rotary vane pump and specialized power steering fluid to create hydraulic pressure, which greatly amplifies the force of the driver’s input when translated into the axle. The pump pulls energy from the car’s engine, pulling fluid from the return line and into a designated output near the rack and pinion, where your steering is translated into turns.
The pump runs even while the car is idle and has a pressure relief valve to avoid overpressure during higher engine revs. The driver’s input is the next step. While the hydraulic pressure on either side of the car is equal when the wheel is being held steady, applying torque to the steering wheel opens the valves around the rack and pinion, releasing high-pressure fluid and aiding in the turning of the car.
Hydraulic power steering has two distinct disadvantages: hydraulic fluid and a pump that is constantly running. The rotary pump runs even while the engine is idle, drawing (and wasting) power. As the fluid ages, it becomes compromised and must be regularly flushed out and replaced. An aging hydraulic power steering system is also more prone to faults and leaks, which immediately kill the power steering as the whole system loses pressure. The good news is that you can still steer a car that utilizes a broken hydraulic power steering system – the steering just becomes a lot harder.
Hydraulic power steering went out of style for the most part in the 2000s. Some of the earliest examples of electric power steering came out of Japan, and eventually, most of the market began utilizing electric power steering as the modern automobile slowly started to develop its own complex nervous system of electrical systems and sensors.
Electric Power Steering
Electric power steering uses an electric motor rather than hydraulic pressure. The motor is controlled by a computer that senses steering wheel movement and vehicle speed. When the driver turns the wheel, the computer sends signals to the motor to assist in turning the wheels. This system is more efficient and adaptable than hydraulic power steering, as it doesn’t rely on fluid and has fewer components to maintain.
Most modern electric steering systems will generally apply the most force on the wheels when the car is stationary (making turning while parking very easy) and less force when the car is at higher speeds, so you’ve got the feeling that you’re slowly pulling into the next lane. Many modern cars with electric steering systems still allow you to steer the car if something goes wrong with the power steering.
Drive-By-Wire and Electrohydraulic Steering
Some vehicles use technologies that entirely separate the steering wheel from the vehicle’s wheels, particularly heavy-duty trucks, and some modern construction vehicles, utilize completely electric or electrohydraulic power steering while completely removing the physical connection between the steering wheel and the wheels of the vehicle.
A few cars have also adopted this technology for the rear wheels, coupling traditional power steering assistance in the front wheels with steer-by-wire technology in the rear. Fully steer-by-wire cars for personal use are fairly rare and will probably remain rare for a while.
When Should You Stop by a Shop?
Power steering systems aim to reduce the physical effort needed to steer a vehicle, especially at low speeds or when stationary. They enhance maneuverability, making driving more comfortable and less strenuous for the driver. But when they go wrong, drivers are left with cars that are either much more difficult to turn or incredibly unresponsive.
Worn-out systems can result in jerky or erratic steering, and if your car is older and running on fluids, then you might be subjected to stiffness, sudden whining or groaning noises when steering, or loss of power steering due to a leak. Sensor issues in electronic power steering systems can be dangerous, as your EPS might spontaneously start and stop, or lead to problems with potential road conditions as the car no longer translates things like poor traction and slippery roads into the steering wheel.
It’s best not to wait for issues to show up. Always be sure to regularly visit an auto shop such as Blu Automotive for maintenance, and have your steering inspected as often as the manufacturer recommends.
