Moparts
Power Steering Fluid
Posted By: Pyper70
Power Steering Fluid - 05/09/14 05:51 PM
I have a bottle of the good old fashion Chrysler Steering fluid from the 90s but I reserve it for my own vehicle.
Moving on to address the slop in the steering on this 72 RR, I am replacing the steering box with a freshly rebuilt one from Firm Feel. The local shop brings fluids and additives from the States and he has Castrol GT Power Steering fluid. Looking on their website I can't read anything about the product. Will this stuff work or is nothing more than ATF fluid in a fancy bottle?
Posted By: stumpy
Re: Power Steering Fluid - 05/09/14 07:13 PM
Any power steering fluid will work. Be warned that power steering fluid is a much different fluid than ATF. You don't need any high dollar brand. Don't use ATF it wasn't made to be used for steering fluid.
Posted By: pattyboy 572
Re: Power Steering Fluid - 05/09/14 09:23 PM
can not compare the lubrication properties of trans fluid to power steering...not the same properties... use power steering fluid
Posted By: John_Kunkel
Re: Power Steering Fluid - 05/09/14 11:37 PM
http://www.valvoline.com/products/consum...ission-fluid/34"Other applications include air compressors, general purpose hydraulics and
power steering system"
Posted By: stumpy
Re: Power Steering Fluid - 05/10/14 12:24 AM
It could be used for power steering but not what is recommended by Mopar or anyone else. I also bet firm feel would not warranty any part failures if you told them that is what you used in the system.
Posted By: ahy
Re: Power Steering Fluid - 05/10/14 12:27 AM
Originally ATF was recommended. Old ATF formulas like Dexron and Type F worked OK as PS fluid. Newer formulas maybe not so much. I would run the PS fluid personally.
Posted By: John_Kunkel
Re: Power Steering Fluid - 05/11/14 12:39 AM
Quote:
It could be used for power steering but not what is recommended by Mopar or anyone else.
A great many threads on this forum are devoted to circumventing what the factory recommends.
Every time this subject is broached the comments are predictable...."don't do it", "it's not formulated the same" but nobody has ever provided proof of damage that can be 100% attributed to using ATF.
Posted By: 62maxwgn
Re: Power Steering Fluid - 05/11/14 02:48 AM
Quote:
Quote:
It could be used for power steering but not what is recommended by Mopar or anyone else.
A great many threads on this forum are devoted to circumventing what the factory recommends.
Every time this subject is broached the comments are predictable...."don't do it", "it's not formulated the same" but nobody has ever provided proof of damage that can be 100% attributed to using ATF.
John,the only fact that I can attest to is that about 30 yrs ago I put ATF in a new pump on a 65 Monaco.One year later the ATF was almost black and you could get a black film on you finger just by wiping it on the inside of the reservoir.I cleaned everything,put in power steering fluid and and the color never changed after that. 
Posted By: stumpy
Re: Power Steering Fluid - 05/11/14 03:02 AM
I'm no engineer but when all the automotive manufacturers call for power steering fluid and not ATf there must be a good reason. I do know that ATF is thinner than power steering fluid which tells me it lubes better when hot and for a longer time.
Posted By: cjskotni
Re: Power Steering Fluid - 05/11/14 03:09 PM
Quote:
I'm no engineer but when all the automotive manufacturers call for power steering fluid and not ATf there must be a good reason. I do know that ATF is thinner than power steering fluid which tells me it lubes better when hot and for a longer time.
I don't get why people even want to run non-recommended fluids here. Am I missing something where ATF is a fraction of the price of power steering fluid or something?? Maybe it's the 'cool' thing to do? 
Posted By: 6PakBee
Re: Power Steering Fluid - 05/11/14 03:29 PM
I can only post what the FSM says.
Posted By: John_Kunkel
Re: Power Steering Fluid - 05/11/14 07:18 PM
Quote:
I'm no engineer but when all the automotive manufacturers call for power steering fluid and not ATf there must be a good reason.
OK, let's look at the reality; when the change was made from Type "A" ATF to dedicated P/S fluid, neither the steering box nor the pump changed in design, in fact, many parts in both remained unchanged until the end of production (even same P/N).
For many years you would go to your LAS and find P/S fluid designated (by automotive engineers) for certain brands only but nowadays you find "one size fits all" P/S fluid that is suitable for all makes.
Perhaps I tend to over-simplify things but this tells me it doesn't make a hill-a-sh*t difference what you use. Anecdotal experiences of failures without lab tests mean nothing that's why I stated "nobody here has ever provided proof of damage that can be 100% attributed to using ATF.".
Why deviate from the recommended fluid? To keep from having to stock dozens of different fluids when one will do the job of many.
Posted By: stumpy
Re: Power Steering Fluid - 05/11/14 08:35 PM
I would think the changes to the seals composition over the years would have something to do with the need to use the correct fluid. I'll bet you only have one weight oil for all your cars also. A sledge hammer will do the job of a tack hammer but that doesn't mean it you should use it to hang pictures.
Posted By: John_Kunkel
Re: Power Steering Fluid - 05/11/14 09:53 PM
Seal compatibility is another often cited myth, look at the P/N of seals/O rings in late seventies boxes and you'll see numbers like 15xxxxx or 17xxxxx that date back to the Type "A" days.
Posted By: Pyper70
Re: Power Steering Fluid - 05/11/14 10:23 PM
I didn't mean to cause such a stir with this...I just don't have the luxury of ordering from Summit because they won't ship the fluid internationally.
I am going to call Firm Feel tomorrow and ask them if they think the Castrol is sufficient for the job at hand.
Posted By: stumpy
Re: Power Steering Fluid - 05/11/14 10:37 PM
Quote:
Seal compatibility is another often cited myth, look at the P/N of seals/O rings in late seventies boxes and you'll see numbers like 15xxxxx or 17xxxxx that date back to the Type "A" days.
Just because the part number is the same doesn't mean the rubber is the same. BTW did you look at the FSM page above where it says NOT to use type A trans fluid?
Posted By: snuggles
Re: Power Steering Fluid - 05/11/14 10:42 PM
I have nothing proven to add. I did however put atf in a ps system after an engine swap. After the atf the pump leaked a lot. Would I do it again? not a chance. Scientific? not at all.Wrong conclusion? possible.
Anybody know what the seals are made of? It could be looked up in an o-ring handbook to see if they are good for both fluids. I do know I would never put ps fluid in a trans. Beyond that who knows.
Posted By: 1970A66
Re: Power Steering Fluid - 05/12/14 02:42 AM
Dick at FF told me to "use any quality PS fluid" in the stage II box I bought from him. I took that to mean a reputable brand.
Posted By: Pyper70
Re: Power Steering Fluid - 05/12/14 07:12 PM
I just got off the phone with Dick at FF and he said the Castrol is fine. Just in case anyone looks through a search later on and finds this thread.
Now I am off to paint the gearbox all nice and purty
Posted By: John_Kunkel
Re: Power Steering Fluid - 05/12/14 09:06 PM
Quote:
Just because the part number is the same doesn't mean the rubber is the same.
If the part changed the part number would change.
Quote:
BTW did you look at the FSM page above where it says NOT to use type A trans fluid?
Did you read my comment about circumventing the factory recommendations?
lots of fluids can be interchanged. If your purchasing clutch fluid just look at the bottle. It IS brake fluid. Dot 3. So it really is a good question to ask but PS and ATF would not fly in my book. different viscosity and pressure tolerances.
Posted By: John_Kunkel
Re: Power Steering Fluid - 05/13/14 06:47 PM
So, you're saying that the pressures have changed since ATF was the recommended fluid? FSM's say they're the same. Viscosity? Nope.
Posted By: stumpy
Re: Power Steering Fluid - 05/13/14 06:54 PM
When did the factory recommend ATF?
Posted By: skicker
Re: Power Steering Fluid - 05/13/14 08:23 PM
Posted By: John_Kunkel
Re: Power Steering Fluid - 05/13/14 08:52 PM
Quote:
When did the factory recommend ATF?
My '57 FSM specifies ATF Type "A" Suffix "A" as do most from the fifties/early sixties.
Posted By: jglen490
Re: Power Steering Fluid - 05/13/14 09:08 PM
Maybe the FSM requirement has changed sometime in the past 50 years "just" so someone could sell a more expensive PS fluid - but I doubt it.
Just like the change in requirement from the mistake of "use Dexron" in the A604 was corrected to ATF+3 and then ATF+4, experience changes many things; and sometimes without the need to validate that experience in a laboratory setting.
Posted By: John_Kunkel
Re: Power Steering Fluid - 05/13/14 09:23 PM
The early ATF contained sperm oil, the use of which was outlawed in the late sixties; this required the development of costly additives to serve as a substitute for the whale oil.
I suspect that the use of dedicated P/S fluid came about because the exotic additives in ATF simply aren't needed in P/S systems. (that doesn't mean it's detrimental to use it)
Posted By: GODSCOUNTRY340
Re: Power Steering Fluid - 05/14/14 04:20 AM
Explain this!
Posted By: stumpy
Re: Power Steering Fluid - 05/14/14 04:35 AM
What's it from?
Posted By: skicker
Re: Power Steering Fluid - 05/14/14 01:29 PM
Quote:
What's it from?
Looks like a p/s reservoir from a hydroboost set-up for a factory plow truck. 
Posted By: jglen490
Re: Power Steering Fluid - 05/14/14 07:36 PM
Old cap.
Posted By: hooziewhatsit
Re: Power Steering Fluid - 05/14/14 10:56 PM
I recently got a rebuilt box for my 72 W200, and asked them about ATF/PS fluid.
"We are good with ATF your system was designed around using ATF for 30 plus years until someone decided they had something better, but any of the p/s fluids are good."
I put in ATF since I had a couple quarts on hand.
Posted By: GODSCOUNTRY340
Re: Power Steering Fluid - 05/15/14 04:58 AM
Nice try Quint, but it's a power steering pump from a 1968 Chebby truck.
Posted By: Pyper70
Re: Power Steering Fluid - 05/15/14 10:46 PM
I went to a few places today to ask for Castrol GT PS Fluid...every place I went to...the kid pulled Dexron-Mercon III off the shelf...and I shook my head and educated them...the owners of the shops stood by the employee...Finally I drove 45 miles today to a Canadian guy who brings parts from Montreal here...and bought 6 bottles of this stuff. Its been sitting on the shelf so long, the bottles have yellowed.
Posted By: GTX MATT
Re: Power Steering Fluid - 05/15/14 11:32 PM
There are still some late model cars that call for ATF for the power steering systems, most notably Subaru.
Posted By: stumpy
Re: Power Steering Fluid - 05/15/14 11:44 PM
Chevy, Subaru? Did any one notice we are discussing power steering fluid in a Mopar which does not recommend ATF usage. Subaru also had a two stroke motor but I wouldn't recommend using a 50:1 blend of gas and oil in our Mopars.
Posted By: Sport440
Re: Power Steering Fluid - 05/16/14 12:06 AM
Quote:
Nice try Quint, but it's a power steering pump from a 1968 Chebby truck.
Yep, Lots of Chevy trucks of that era and Later, had the ATF stamped PS cap. Even saw a similer cap on a Chevy 10 ton Dump truck. Similer pumps but power steering box was huge and expensive.
GM had No worries using Tranny fluid in the PS units. Heck They Even Stamped the Caps. 
Posted By: GODSCOUNTRY340
Re: Power Steering Fluid - 05/16/14 12:11 AM
Quote:
Any power steering fluid will work. Be warned that power steering fluid is a much different fluid than ATF. You don't need any high dollar brand. Don't use ATF it wasn't made to be used for steering fluid.
Just reacting to your post stating ATF wasn't made to be used for power steering fluid.
Posted By: stumpy
Re: Power Steering Fluid - 05/16/14 12:14 AM
We are discussing MOPARs not GM or any other off brand.
Posted By: GODSCOUNTRY340
Re: Power Steering Fluid - 05/16/14 12:23 AM
Quote:
It could be used for power steering but not what is recommended by Mopar or anyone else. I also bet firm feel would not warranty any part failures if you told them that is what you used in the system.
Here you state it's not recommended by Mopar or anyone else. I'd like to agree with you but then we'd both be wrong. 
Posted By: stumpy
Re: Power Steering Fluid - 05/16/14 12:42 AM
OOps, I did over step but since the 70s power steering fluid has been the more excepted alternative to ATF by most manufacturers.
Posted By: John_Kunkel
Re: Power Steering Fluid - 05/16/14 06:53 AM
"Overstatement" is the hallmark of this thread.
