What Is Power Steering Fluid? How To Check

You can thank power steering for the quick and easy maneuvers you’re used to behind the wheel. 

Power steering reduces the physical input necessary to turn the steering wheel — and, by extension — the front wheels of your vehicle. In fact, power steering and the fluid that drives it are more vital to your vehicle’s operation than you might think. 

The guide below explores the concept of power steering fluid, including how to check and change it. Routinely inspecting and replacing the power steering fluid is vital to your vehicle’s optimal function. 

What Is Power Steering Fluid?

Power steering fluid is a type of automotivehydraulic fluid that contains additives that cool, lubricate, and fight corrosion. Typically red, amber, or light brown, the fluid enables the power steering system to function properly. 

Power steering fluid is one of the many fluids that support your vehicle’s operation, including DEF fluid (if you have a diesel), windshield washer fluid, and synthetic or conventional oil. 

Most vehicles’ steering systems are powered by electronics or hydraulics. Electronic steering systems do not require power steering fluid but use a complex system of sensors to adjust the front wheels. Many electric vehicles (EVs) use electronic steering systems. 

Hydraulic power steering systems have existed for much longer than electronic systems. The power steering fluid they require to function comes in several formulations, from mineral-based and synthetic to a semi-synthetic blend. 

To determine which power steering fluid formulation your car needs, check your owner’s manual for exact specifications. 

How To Check Power Steering Fluid

Checking the power steering fluid should be part of your vehicle’s routine maintenance, along with inspecting the oil, brake fluid, and coolant levels. By performing regular visual inspections, you can detect potential fluid leaks or concerns sooner and avoid inconvenient breakdowns and costly repairs. 

Here’s how to check a car’s power steering fluid: 

1. Open the hood and locate the power steering fluid reservoir. It’s typically smaller than your coolant overflow and windshield washer fluid reservoirs and located near the firewall on the driver’s side. 
2. Before inspecting the fluid inside, note the level and any residue on the reservoir’s exterior that might indicate a leak. Pay particular attention to any fresh fluid that might give away the leak’s location. 
3. Unscrew and remove the reservoir’s cap. Set it aside for a moment. 
4. Inspect the power steering fluid for color, smell, and consistency. 
5. If the vehicle’s power steering fluid reservoir doesn’t have a level indicator, you can manually check the levels using the provided dipstick — similar to how you’d check the oil. Remove the dipstick, wipe it clean, place it back in the fluid, and gauge the level by the amount of fluid that appears on the dipstick. 

If the power steering fluid smells unpleasant or appears discolored, contaminated, or foamy, replace it immediately. If the fluid checks out but the level is low, top it off with the appropriate power steering fluid as recommended by the manufacturer. Note how much you poured in to determine if the system leaks. 

When To Replace Power Steering Fluid 

In a perfect world, you’d only have to replace your vehicle’s power steering fluid at the intervals specified in the owner’s manual. However, due to normal wear and tear, power steering fluid naturally deteriorates over time. 

Routine inspections ensure your vehicle has viable power steering fluid to make the necessary turns as you drive. 

In addition to replacing contaminated power steering fluid, you should also check the fluid if you feel a difference in steering or hear strange noises as you turn your vehicle. A fuel efficiency drop can also indicate that your power steering might need replacing. Investigating the root cause of these issues is key, as they may involve more than just the power steering fluid. 

For example, loose or stiff steering coupled with whining noises can indicate a malfunctioning or failed power steering pump. A damaged steering rack mount can cause clunking or knocking as you turn. 

In some cases, the sound or problems may arise from a loose or broken power steering belt, which uses the engine’s power to operate the power steering pump. 

How To Change Power Steering Fluid

You don’t have to get under your vehicle to change its power steering fluid. However, there are certain protocols you should follow to ensure you’ve removed the old power steering fluid that’s no longer viable and replaced it with fresh fluid. 

Here’s how to change a vehicle’s power steering fluid: 

1. Open the power steering fluid reservoir and remove as much of the old fluid using a turkey baster or fluid pump as possible. 
2. Refill the reservoir to the “MAX” or “FILL” line using a funnel and the proper power steering fluid, according to the manufacturer's recommendations. 
3. Keeping the power steering fluid reservoir cap off, start the engine. 
4. Turn the steering wheel left and right — while avoiding full steering lock — to bleed air from the system, repeating a few times per side to circulate the fluid. 
5. Shut the engine off and inspect the power steering fluid reservoir and ground beneath the vehicle for leaks. 
6. Top off the power steering fluid until the level reaches the “MAX” or “FILL” line. 
7. Replace the power steering fluid reservoir cap, ensuring a tight fit. 

After initially exchanging the old fluid for the new one, you can repeat the process to ensure that very little, if any, old power steering fluid remains in the system. While this step isn’t necessary, it can offer peace of mind. Remember to note the date and mileage you changed the power steering fluid in your vehicle's maintenance records. 

Can You Swap Power Steering Fluid for Automatic Transmission Fluid?

Although it’s rumored that you can use automatic transmission fluid (ATF) in place of power steering fluid, it’s wise to proceed cautiously with this exchange. 

Certain automotive manufacturers designed their power steering systems to accept ATF, but these makes and models are more of an exception than the majority. Refer to the owner’s manual to determine which power steering fluid the system requires, and stick with this formulation for best results. 

Maintain Your Vehicle With Premium Products and Solutions

Maintaining your vehicle with superior power steering fluid ensures its reliability and performance. The experts at Cadence can help connect you to the automotive maintenance solutions necessary for optimal function. 

Call 336-629-2061 to speak to a representative and discover how our team delivers value at every turn. 

Sources:

Power Steering Fluid Maintenance & Symptoms | RepairPal

Power Steering - How Car Steering Works | HowStuffWorks

Hydraulic Fluids | Public Health Statement | ATSDR

AUTOMATIC TRANSMISSION FLUID | The Petroleum Quality Institute of America