78 Power Steering fluid
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Joined: Apr 2008
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From: Drummonds TN
78 Power Steering fluid
I will be replacing some components of the power steering system in my 78. It was suggested that I may be using the wrong Power Steering fluid, which is prestone. Is there a certain fluid I should be using? I certainly want to use the correct fluid with the rebuilt system.
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From: Muskegon MI
Team Owner
Joined: Jul 2004
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From: Redondo Beach, California
Jim O'Shea, I believe, has mentioned GM Power Steering fluid as a first choice.
With an all new dry Power Steering system, I initially when to a local auto parts store. I noticed that all of the power steering brands for sale advertised something to the effect that they were effective at stopping leaks. To me this was a warning that these fluids were being marketed to people driving worn daily drivers on their last legs (i.e. beaters). And who knows what was in them that was going to stop leaks. With all the money in my new PS system, this was a turn off. I just drove to the local Chevy dealer and got a container of GM Power Steering fluid, which is what I should really have been looking for in the first place.
With an all new dry Power Steering system, I initially when to a local auto parts store. I noticed that all of the power steering brands for sale advertised something to the effect that they were effective at stopping leaks. To me this was a warning that these fluids were being marketed to people driving worn daily drivers on their last legs (i.e. beaters). And who knows what was in them that was going to stop leaks. With all the money in my new PS system, this was a turn off. I just drove to the local Chevy dealer and got a container of GM Power Steering fluid, which is what I should really have been looking for in the first place.
Le Mans Master
Joined: Jul 2000
Posts: 6,001
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From: Saginaw Michigan
I have no idea who formulated the PS fluid that is sold at K-mart, Pep Boys, NAPA, etc. This isn’t to say that it is bad. However, the amber colored GM fluid is the only fluid that is specifically formulated to operate with Saginaw power steering pumps.
The GM fluid has been certified and tested in GM durability test vehicles for millions of miles. It also is the only fluid that have been durability tested in the Saginaw Steering Gear engineering labs for hundreds of thousands of hours. All of the rubber compounds that are used in the seals, hoses, etc in the production GM power steering system are tested in the materials laboratory for compatibility with the fluid.
Genuine GM power steering fluid is available through any GM dealer. The GM part number for a quart of power steering fluid is 89020661. The previous GM part number for power steering fluid was 1050017. Both fluids work equally well. I recommend that you drain whatever fluid is currently in your system and replace it with genuine GM power steering fluid.
Jim
The GM fluid has been certified and tested in GM durability test vehicles for millions of miles. It also is the only fluid that have been durability tested in the Saginaw Steering Gear engineering labs for hundreds of thousands of hours. All of the rubber compounds that are used in the seals, hoses, etc in the production GM power steering system are tested in the materials laboratory for compatibility with the fluid.
Genuine GM power steering fluid is available through any GM dealer. The GM part number for a quart of power steering fluid is 89020661. The previous GM part number for power steering fluid was 1050017. Both fluids work equally well. I recommend that you drain whatever fluid is currently in your system and replace it with genuine GM power steering fluid.
Jim
Le Mans Master
Joined: Jul 2000
Posts: 6,001
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From: Saginaw Michigan
Originally in the 1950’s, automatic transmission fluid (ATF) was specified for use in both General Motors automatic transmissions and also for their power steering systems. But as vehicles got heavier, engines bigger, and temperatures hotter, the requirements for the two different systems changed. So around the same time, Saginaw Steering Gear Division and Texaco began testing and developing a fluid for power steering and specifically for use with Saginaw pumps.
That is why some of the early power steering reservoir caps had ATF specified as the proper fluid to use. After a specific power steering fluid was developed in the early 1970s all the later pump caps and the owner's manuals have said to use "Approved Fluid". The GM power steering fluid is approved for use in any vehicle with a Saginaw power steering pump.
ATF has not been specified for use in power steering systems over that last 30 to 40 years. I believe that Ford Motor Company may have had a special "common" fluid for automatic transmissions and power steering. They didn't use Saginaw pumps either.
Jim
That is why some of the early power steering reservoir caps had ATF specified as the proper fluid to use. After a specific power steering fluid was developed in the early 1970s all the later pump caps and the owner's manuals have said to use "Approved Fluid". The GM power steering fluid is approved for use in any vehicle with a Saginaw power steering pump.
ATF has not been specified for use in power steering systems over that last 30 to 40 years. I believe that Ford Motor Company may have had a special "common" fluid for automatic transmissions and power steering. They didn't use Saginaw pumps either.
Jim
