I know OEM is the best but you may not always have ready access to it.

Here is some interesting information from one of the largest parts rebuilders in the US. Click on the Fluid List link in the bottom paragraph of their article to see a list of fluids they have tested.

http://www.cardone.com/tech-help/ste...-created-equal

 

The only difference between power steering fluid and automatic transmission fluid is the color....also that's why two different colors is to see what is the source of the leak...So I put trans fluid in my power steering reservoir and it works just fine...I also use it in my hydraulics for the Meyers snow plow on my Blazer

But not the one in the Vette.....

 

Back in the 1960s power steering fluid and automatic transmission fluid was the same. However, as engines got bigger and more powerful General Motors determined that the automatic transmissions required a different fluid specification. So the Fuels and Lubricants Section (a part of General Motors Research at the GM Technical Center) developed a new and different fluid for AUTOMATIC TRANSMISSIONS.

This new Dexron automatic transmission fluid (Type A, suffix A) was basically developed and released in the late 1960s without much thought as to its use with power steering. Saginaw Steering Gear Division was very concerned that automatic transmission fluids could be continually changed to meet MIGHTY POWERTRAIN needs and eventually could actually become inferior for useage with Saginaw power steering pumps.

So Saginaw Steering Gear Division worked independently with Texaco to develop a unique fluid just for power steering. So for the last 40 years General Motors has always had a unique power steering fluid available through GM dealerships. It is the amber colored fluid available as GM (89020661) or AC Delco (89021182).

This fluid is specifically forumlated to work with the Saginaw power steering pumps. It has very good anti-foaming characteristics and very good lubricating qualities for the bushings and plates inside the Saginaw pumps.

The only power steering fluid that has been tested and continuously used for the last 40 years has been the GM approved fluid listed above. This isn't to say that other fluids are bad. But none of them have been subjected to millions and millions of miles of actual customer useage. Nor have and of them been as rigorously laboratory and fleet tested like the approved GM fluid.

So in a nutshell, automatic transmission fluid and power steering fluid are not the same. The most tested and most likely the best fluid for use with a Saginaw power steering pump is the approved GM power steering fluid.

Thank you STOCK 76 for the information on the Cardone website. I reviewed their listing of Cardone approved power steering fluids. I noted that GM power steering fluid is not on their list. I have sent them a message asking if they have tested the GM fluid and whether or not it meets GM specifications or not. Very strange that the OEM fluid is not on their list.

Jim Shea

 

Like most business interests in this "modern era", if they don't sell it, it just isn't acknowledged. Why list something that you can't make any money on...even if it IS better for the customer???

[modern day business "ethics"]...

 

I use Hurst Trick shift in my 650 hp C4 ford and corvette also run it in my P.S. systems, it runs cooler and don't foam up.

 

That's Ford type F used in racing transmissions...GM`s Dexron is really designed for a smooth shift as I understand it...Where by Type F really shifts hard and positive, the reason it's used for racing....And the reason I use it.......

F is recommended by Racing automatic transmission companies where parts of seconds is the difference in winning and losing....However back to the subject, it also works for PS units too......

 

You can also pour motor oil into your power steering system. It will provide power assist for a while. But it won't match the durability of the GM power steering fluid.

One other point, it would be good if Cardone would outline what type of tests and what criteria that they use to evaluate various fluids. Looking at their website, I can't find them.

Saginaw has a whole battery of laboratory tests that probe the limits of pump and fluid durability. They use power steering pumps right from their manufacturing plant and fluid right from the supplier which is taken from fluid batches used on vehicle production lines.

Jim

 

I was never a big believer in the OEM specified power steering pump fluid in PS pumps either. However, I recently had a change of heart. A few Anecdotes:

Rebuilt the 78 PS pump myself and used autozone PS fluid after the rebuild, AND the pump whined occassionallly on hard turns-never did prior to the rebuild for a leaking pulley shaft bushings. Switched to AC delco fluid. All good now!

#2-2001 GM Pontiac Grand Prix:changed the PS fluid at 120,000 miles to Autozone PS fluid. Pump noisy. Switched to GM Delco fluid. All good at 145,000 miles now.

#3-1994 Mustang GT convertible with 25,000 miles on the car and I was using PS fluid instead of Ford's recommendation of Automatic Tranny Fluid Type F. Developed a seal leak requiring a new rack and pinion. BTW-Installled an A1 Cardone 2003 Cobra Rack in the 94. I use Ford Type F now. No substitutes.

PS is often overlooked as a regular maintenance item. The fluid needs to be changed periodically (I use a Turkey baster to suck the fluid out of the reservoir) especially on cars that have a factory PS pump cooler like my Mustang and Chrysler 300. I suck the fluid out of the PS reservoir once a year and replace with Chrysler specified Trans Fluid-ATF+4. No messing around with PS pumps any more.

Sometimes I have to learn the hard way-LOL!