Simply put, power steering is what helps you turn the steering wheel with ease. Power steering systems today change the ease of steering to enhance the feel for the driver. The act of steering the vehicle is actually achieved between the steering wheel and a gear system. The rack is a linear gear that, instead of being round, is long and flat with prongs on one side. The rack is attached to the steering spindles by the tie rods. The pinion is a circular gear that attaches to the steering shaft attached to the steering wheel. When the wheel is turned, the pinion gear rotates, moving the rack back and forth making the wheels turn either left or right. This is a quick explanation in order to give you an idea of just how much goes into the power steering to make it as easy as possible on the driver.
Hydraulic, or HPS (high pressure steering), consists of a recirculating ball steering gear or the rack and pinion gear. Both are considered power steering assist systems, allowing the driver to steer the vehicle if the engine, which powers the power steering pump, isn’t running and thus not supplying fluid to the steering gear. Hydraulic systems use the power of the engine with the use of a belt attached to the pump to circulate power steering fluid throughout the system.
What does power steering fluid do? This fluid transmits the power in power steering. The power steering pump circulates the fluid under pressure, enabling the hydraulic piston in the steering gear to move. Because of the improvements in modern vehicles, the systems of today are able to sense the speed of the vehicle and slow the input from the steering wheel to the steering gear to reduce the sensitivity at higher speeds for safety. This is just one of the many ways that the system has been improved overall over the years.
Over time, dirt, and debris along with weakened power steering components, may contaminate power steering fluid. That’s why it’s recommended to have the power steering fluid flushed ~ 30,000 miles. Avoiding this service, could cause the pump to work harder and wear out prematurely. Thus, causing more issues and potentially doing severe damage to certain components of your vehicle. In between flushes you can check the fluid level. Use our quick and easy guide and reference your owner’s manual for specific details for your vehicle:
- Check the fluid after the car has been running and warmed up. The vehicle is normally checked with the vehicle shut off.
- Locate the power steering reservoir (usually indicated in the owner’s manual) and identifying the label on the reservoir cap.
- Remove the cap.
- If the reservoir is made of clear plastic, identify the full and low indicator lines on the outside of the tank to determine the fluid level. If the reservoir is metal or obscure, using the dipstick, wipe the fluid on the dipstick off with a clean rag. Then, dip the dipstick back into the reservoir and check the level. The dipstick will indicate the fluid level remaining in the tank.
EPS, or electric power steering is a bit simpler as the vehicle’s computer is responsible for easing the steering process. The EPS system is most often equipped with a small electric motor that is either placed at the base of the steering column or directly on the steering rack. Unlike the hydraulic system, EPS does not use the power of the engine, which increases fuel economy. When a driver wants to turn, the computer is able to translate the turning of the steering wheel to an electric motor that assists in moving the rack and pinion back and forth. Similar to HPS, the electric system varies the sensitivity at higher speeds for increased safety.
When turning becomes a difficult process, a fluid leak or component failure may be to blame. If the vehicle is hard to control or has too much “free play” and wanders, it’s time to take your vehicle to a certified repair center. Did you know that improperly mounted or balanced tires can also affect the system? It is important that the vehicle is running at 100% all the time so that one small issue, doesn’t over time cause another issue with something that works alongside it.
A technician will inspect the vehicle and provide a detailed explanation on what is needed to resolve your vehicle’s steering issues. A flush or even a tire balance may be all your vehicle needs to alleviate the difficulties in the power steering system.