Understanding Power Steering Fluid

Power steering fluid keeps cars and trucks running.

It allows you to steer and turn your vehicle with little to no effort. And if you don’t stay on top of flushing and replacing your vehicle’s power steering fluid as necessary, the power steering pump will start to deteriorate.

But what exactly is power steering fluid? How can you learn how to avoid problems with it?

Read along as Brian Murphy, Education & Development Program Manager at Universal Technical Institute (UTI), answers the question, “What is power steering fluid?” You’ll learn about the different types of power steering fluid, how to change power steering fluid and other key information about how power steering fluid keeps cars running smoothly!

Key Summary Points

• Power steering fluid is essential for the proper functioning of a vehicle's steering system.
• It reduces the effort required to turn the wheels and lubricates the moving parts in the system.
• Power steering fluid is typically red, amber, pink, light or clear, but if it is dark brown or foamy, it needs to be changed.
• There are different types of power steering fluid, including automatic transmission fluid (ATF) and synthetic fluid.
• It is important to follow the manufacturer's guidelines for changing power steering fluid, typically every five years or 50,000 miles, to prevent damage to the system.

What Is Power Steering?

The power steering system in a vehicle uses engine power to reduce the amount of effort needed to turn the front wheels of a vehicle. It helps the driver have increased control and handling of a vehicle.

Power steering systems can be hydraulic or electric. Hydraulic systems use fluid to apply pressure to the system, which helps turn a car’s wheels. An electric system uses an electric motor and various sensors to detect how much force a driver is applying to the steering wheel. Then, it determines how much assist should be added by the system.

What Is Power Steering Fluid?

Power steering fluid is the hydraulic fluid used in the steering system. It creates a hydraulic link between the steering wheel and the front wheels, which decreases the amount of effort required to turn the wheels.

It also lubricates the moving parts within the steering system, suppressing foaming and preventing corrosion in the power steering gear and steering pump. This critical function enables power steering fluid to maintain optimal vehicle operation.

What Color Is Power Steering Fluid?

Most commonly, power steering fluid is red, amber, pink, light and/or clear. If it’s dark brown or foamy, it probably needs to be changed.

Where Does Power Steering Fluid Go?

The power steering fluid reservoir is located under the hood, usually on the passenger’s side of the vehicle, although sometimes it can be found on the driver’s side. The container is usually white or yellow with a black cap that has the words “power steering” or “steering fluid” on the top.

Read: What Is Car Engine Coolant?

What Are the Types of Power Steering Fluid?

Automatic transmission fluid (ATF) is the same fluid used inside the automatic transmission. ATF can also be used in some power steering systems. Some ATF types include Dexron and Mercon.

Synthetic power steering fluid is a non-oil-based fluid created in a lab. It’s usually specifically engineered for the particular car or system for which it’s being used. Most newer vehicles use synthetic power steering fluid.

There are also non-synthetic, mineral-based oil power steering fluids that may be used in applications that accept ATF fluids.

A lot of people wonder, “Is power steering fluid the same as transmission fluid?” While ATF and power steering fluid are both hydraulic fluids, ATF features different modifiers and detergents specifically designed to remove dirt and grease from the transmission system.

What Are Power Steering Fluid Specification Standards?

Power steering specification standards are requirements for the viscosity, detergents, additives and other components of the fluid. Meeting these standards ensures the power steering fluid is safe to use in a specific vehicle.

These specification standards are created by standardization organizations. For example, DIN 51 524T3 is the standard given by the German Institute for Standardization, while ISO 7308 is the standard given by the International Organization for Standardization.

Certain vehicles will require that power steering fluid meets both DIN 51 524T3 and ISO 7308 standards. There may be other power fluid standards for certain types of vehicles, like those made by Japanese automakers.

Read: What Is Brake Fluid?

When Should You Change Power Steering Fluid?

When you should change the power steering fluid depends on the type of fluid used and the volume of fluid in the system. You can locate this information through the original equipment manufacturer (OEM) guidelines. Generally, power steering fluid should be replaced at least every five years or 50,000 miles. There may also be physical warning signs that the power steering fluid needs to be changed. These signs include:

1. Dark color: When you inspect the power steering fluid, it should be light in color. If it’s dark, change it.

2. Dirt, debris or sludge: If you see any dirt, debris or sludge in the power steering fluid, flush the system.

3. Noises when turning: A moaning or whining noise when you turn the steering wheel indicates issues with the power steering system.

4. Difficulty turning the wheel: Difficulty turning the wheel means it’s time to change the fluid.

5. Leaks: If there are leaks, check the power steering fluid level.

To service power steering fluid, drain or flush the old power steering fluid out of the car. Then, replace it with new fluid. Following OEM recommendations and general maintenance guidelines can prolong the functionality of other power steering parts.

If you neglect power steering fluid, it could damage components after it goes bad — components like the power steering pump and power steering rack. Although avoiding power steering fluid maintenance can help you avoid short-term costs, the damage will accumulate and exponentially worsen until you inevitably have to replace your vehicle’s power steering parts, or even the entire system. Compared to repairs that are performed in a timely manner, total part replacements are much more costly.

If a vehicle runs out of power steering fluid, it’ll be much more difficult to turn. In a worst-case scenario, you’ll damage the power steering pump, which may result in a costly replacement.

Read: Milky Oil & Its Dangers

Does Power Steering Fluid Go Bad?

Power steering fluid doesn’t expire. But if it isn’t changed or flushed when needed, it will wear down in the system over time.

What Types of Vehicles Is Power Steering Fluid Used in?

In addition to personal cars and trucks, power steering fluid is used in large diesel vehicles.

Read: What Is Differential Fluid?

Power Steering Fluid FAQs

1. Can you use transmission fluid for power steering fluid?

It depends on the vehicle. Generally, it is not recommended. Some older vehicles might allow it in an emergency, but it’s best to use the fluid specified by the manufacturer.

2. How often should power steering fluid be changed?

Power steering fluid should generally be changed every five years or 50,000 miles, but it's best to follow the specific guidelines provided by your vehicle’s OEM. Regularly checking the fluid for discoloration or contamination can also help determine when it needs to be changed.

3. How much power steering fluid do I need?

The amount varies by vehicle, typically ranging from 1 to 2 quarts. Check your vehicle’s manual for the exact specifications.

4. Can you use brake fluid for power steering fluid?

No, you should not use brake fluid as a substitute for power steering fluid. Brake fluid and power steering fluid have different chemical compositions and are designed for different purposes. Using brake fluid can damage the power steering system and lead to costly repairs. Always use the fluid specified by the vehicle manufacturer for the best performance and longevity.

5. What are the symptoms of contaminated power steering fluid?

Symptoms of contaminated power steering fluid include unusual noises like moaning or whining, difficulty in steering and a change in fluid color to dark brown or foamy. The presence of dirt, debris or sludge in the fluid is also a clear indication that it needs to be flushed and replaced.

Read: What Is Transmission Fluid and What Does It Do?

Learn More About Power Steering Fluid in UTI’s Auto & Diesel Programs

Both UTI’s Automotive Technology and Diesel Technology programs cover topics such as power steering fluid.

In the diesel program’s  Steering and Suspension Systems course, students learn about power steering pumps and truck steering systems by disassembling a steering gear box and mastering other steering system components.^1,33 In the auto program’s Steering and Suspension Systems course, students learn about steering and suspension systems — including steering gearboxes.

To connect with an Admissions Representative and learn more, head to our website to request info or call 1-800-834-7308!

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