Power steering fluid and transmission fluid are both essential to maintaining different systems in your vehicle. But, is power steering fluid the same as transmission fluid? And what functions do they serve?
Power steering fluid is similar to transmission fluid in that they both are classified as hydraulic fluids. However, transmission fluid is required to have specific additives and detergents to help remove contaminants, lubricate metal components, and cool the system.
Truth is – the question of which type of fluid goes where can be complicated enough.
And because both power steering and transmission fluids are considered hydraulic fluids, a common mistake is to assume they are interchangeable.
But that’s not the case – and for good reason.
While these two fluids are quite similar in design, they cannot be used interchangeably due to their subtle differences. Sure, it’s tempting to think they might be interchangeable, but that really isn’t the case.
Learning what type of fluids your car takes is an important part of knowing how to care for it properly. After all, most modern vehicles require six different fluids to operate properly.
So let’s tackle this topic together: is power steering fluid the same as transmission fluid? In this guide, we’ll explain the key differences between these two vital lubricants.
Then we will touch on why it matters for your vehicle. Let’s dive into this!
What’s the Difference between Transmission Fluid and Power Steering Fluid?
Automatic Transmission Fluids (ATF) are designed to help the transmission run smoothly by cleaning, lubricating, and conditioning.
The fluid also aids in cooling the transmission system, preventing the transmission from overheating.
Power steering fluids, on the other hand, are hydraulic fluids that optimize the power transfer in your steering system. Put simply, they minimizing the effort needed to turn the wheels.
The difference between the two is the inclusion of additives and detergents in ATF that make it specialized for transmission use.
Friction modifiers and detergents in ATF are designed to avoid wear and tear on metal components, carry contaminants away, and cool the system.
Power steering fluid on the other hand, does not contain these vital modifiers and detergents.
Can You Mix or Exchange ATF and Power Steering Fluid?
No, you should not mix or exchange power steering fluid for ATF fluid. While true they are both hydraulic fluids, they have differences in function.
Power steering fluid should never be used in place of ATF. Simple put, power steering fluid used in place of ATF would cause costly mechanical problems.
However, if you are in a bind and low on power steering fluid, ATF fluid can be substituted with no risk to the steering system.
Why Are Additives Added to Transmission Fluid?
Automatic transmissions endure a wide range of temperatures, from -60 to +400 ° C. In addition to extreme temperature conditions, the transmission fluid is constantly bombarded with tiny pieces of plastic, metal fragments and other debris.
However additives and detergents added to ATF helps combat these challenging elements by capturing and moving away harmful debris.
Additionally, they lubricate and cool components for optimal performance.
What Will Happen if I Put Power Steering Fluid in The Transmission?
In most cases, the transmission would overheat, and the clutches would begin to slip and burn. Eventually, the transmission would fail, leading to a costly repair bill.
Can You Use ATF in a Power Steering Pump?
Yes, ATF can be used as a substitute for power steering fluid in your power steering system. If you are low on power steering fluid, then ATF will work just fine.
Although not ideal, it won’t have any negative effects on the steering system.
Can You Add Automatic Transmission Fluid ATF to a Continuously Variable Transmission CVT?
Never use ATF fluid in your CVT transmission. Because a CVT transmission operates vastly different than automatic transmissions.
CVT transmissions use a series of belts instead of gears to transfer engine power to the wheels. Which is why, only CVT fluid should be used in a Continuously Variable Transmission.
Final Thoughts
There are lots of similarities between power steering and transmission fluid, but the two are designed for very different purposes.
So just remember, while power steering is classified as a hydraulic fluid, it should never be used in your cars transmission.
Managing Editor
Christopher is an automotive technical writer. When he’s not at the local autocross event, he can often be found working on one of his cars. Specializes in automotive class action law, industry trends, and automotive maintenance. Email me direct, or learn more about us