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Transmission fluid in your power steering

This weekend I am going to replace my old power steering fluid in my 2002 Kia Sedona mini van. Every where I look on line it tells me to use transmission fluid. Is this right? When they sell power steering fluid why would you use transmision fluid? Also how do you know which type of transmission fluid to use?

Are you saying that your owner’s manual doesn’t tell you what fluid to use? That would be unusual.

don’t have one, bought the van used

I’d look at Kia’s website to see if they have an owner’s manual online. But, many car makers do spec Dextron III trans fluid for power steering, like my 2000 Ford Explorer and my '92 Toyota Celica. Many of those off-the-shelf power steering fluids usually meet the same requirements and say so on the bottle. But some require a different fluid, like Honda has it’s own spec fluid and is sensitive to it.

Market niche labeling !
Most transmission fluid -IS- power steering fluid -IS- transmission fluid.
You see this market labeling all over the stores.
Sominex…-IS- Benedril !
Clutch fluid -IS- brake fluid.
And depending on your car’s specs…

Do what you must to get one. I looked at and they don’t list Kia.

Kia has the manual for 2002 Sedona online at
See page 7-40 where they recommend power steering fluid PSF-III

Every where I look on line it tells me to use transmission fluid. Is this right?

20 years ago that was very common. But since then the formula for power steering fluid changed so it was no longer compatible. I guess some companies still use it.

It’s called “Shelf Space”…It’s ALL petroleum oil…Most power-steering systems and other hydraulic pump systems do just fine using Dexron ATF…While servicing your P.S. system, check to see if there is a screen filter in the reservoir protecting the pump inlet line…If these filters get clogged up, the pump can starve for oil and get noisy…

It depends on the car. I went to buy power steering fluid for my wife’s Nissan at the dealer. They told me they did not have any Nissan PS fluid. The tried to sell me a quart of transmission fluid, which they used themselves for service and repairs! So they’re problably the same.

I went to an automotive shop and bought a small bottle of fluid suitable for all cars. It was problably also transmission fluid.

the owners manual says PSF III, I went on Oreily’s web site and their site shows different brands but didn’t see anything on the bottles that said “PSF III”.

I commend you for taking the time to check. Incorrect fluids can cause all form of problems.
Laenir posted the correct info. And, as Mike said, the use of tranny fluid in power steering has a long history. If you think about it, it makes sense. While one system moves the piston that helps steer the wheels, the other moves the pistons that move the tranny’s internals around. Both are very similar hydraulic systems.

don't have one, bought the van used

I gave you the direct link to the manual 2 weeks ago. Same as the one Laenir just posted.

Kia forums say use Mobil syn trans fluid. And do not use dex3 rated fluid. But I don’t own a Kia.

PSF III would be Dexron III. Kia and Hyundai don’t have their own brand of ATF or PSF.