Shop replaced ATF in power steering with power steering fluid. Is this OK?

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scjmc

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The pressure switch (does anyone know what this does on the LS specifically?) blew out and I lost of the fluid in my steering system in about 2 minutes. This happened a ways from the house, so I took the car in rather that fix it myself. I instructed them to replace the pressure switch and then flush and refill the system. When I got the car back I asked them if they refilled the system with Mercon or PS fluid and they said PS fluid. Is this a problem, or is PS fluid fine? NOTE: I am talking about the power steering only the hydraulic fan still has Mercon. Thanks...
 
Some say ATF is better, but I strongly disagree.

PS fluid is meant for the PS PUMP!
ATF is meant for TRANSMISSIONS!

They would make a universal oil that can replace coolant, atf, PS fluid, and wiper fluid now would they? No, each one does its specific job to the best of its abilities :D
 
from the owner's manual...

POWER STEERING FLUID
Refer to the scheduled maintenance guide for the service interval
schedules. If adding fluid is necessary, use only MERCONt ATF.
Click to expand...

it's important to remember - the characteristics of ATF is now much more common in the requirements for most 'pumps' in a car.
 
I know, and I still disagree with it.

Its just my (and many others) opinion, I dont see PS fluid actually hurting a PS PUMP though, but hey maybe its just me.
 
pretty smart engineers that build the requirement for these things.... I'm not smart enough to weigh the actual mechanical tested needs against the actual characteristics of the oil they recommend....
 
transmission=hydraulic pump
power steering pump=hydraulic pump
cooling fan=hyraulic pump

see the connection. ATF is better and cheaper than power steering fluid.
Check page 246 of the owners manual, calls for Mercon. Ford TSB actually calls for Mercon V but why split hairs.

love those guys who still disagree with the engineers!!!!!
 
Last edited:
#1fordfan said:
transmission=hydraulic pump
power steering pump=hydraulic pump
cooling fan=hyraulic pump

see the connection. ATF is better and cheaper than power steering fluid.
Check page 246 of the owners manual, calls for Mercon. Ford TSB actually calls for Mercon V but why split hairs.

love those guys who still disagree with the engineers!!!!!
Click to expand...


Yea! And I'll use 87 octane gas too so I can save the ~$300 a year!!

Any of you experts out there want to tell me whether I'm doing my job right or not? How many miles do I really need between two (or more) airplanes? The book says 3 (or 4 or 5 or 6 or 8 or 10), but we all know that they won't hit at a mile apart. Maybe I should just start running airplanes closer because it's a big sky and they probably won't hit. Maybe I should show up at your place of employment and show you how you're all wrong in the execution of your duties.



Sheesh! What do those engineers know anyway?? :eek:
 
LS4me, I am guessing you might be an air traffic controller, I would also think that the required seperation is based upon past accidents and trying to prevent more accidents.

the engineering is to recommend types of fuel and fluids to give the best results possible without causing unnecessary damage and best performance.

nobody cares if anyone chooses to use whatever they feel like, they are nothing more than recommendations.
 
#1fordfan said:
love those guys who still disagree with the engineers!!!!!
Click to expand...

Are these the same engineers that came up with the hydraulic cooling fan? Because those guys were brilliant and vastly underpaid!!!! Must have been another one of those ideas that looked good on paper.

However I'm confident it was a different engineering group that came up with the sway bar placement and non zerk bushings?

And a different engineering group for the clock spring.

ALL engineers (this goes double for architects) should be required to work in the service end of their chosen engineering discipline for a year before becoming licensed

I worked in structural engineering for over 20+ years and early on I designed a structural steel framing element/connection that couldn't be fabricated.... but on paper it met the seismic requirements, deflection, yield and my design documents indicated very nice welds.... that no fabricator could get to. I got called down to the job site and asked me to follow my own fabrication sequencing.... um well um ohhh
 
I tend to listen to the guy that designed the device as to what is the best fluid to for its use
 
This is another reason why I do all of my maintenance myself. I kept telling myself to remind the shop owner that it took Mercon and not power steering fluid, but I thought to myself that they would check specification/notice the RED ATF sprayed everywhere.
 
#1fordfan said:
LS4me, I am guessing you might be an air traffic controller, I would also think that the required seperation is based upon past accidents and trying to prevent more accidents.

the engineering is to recommend types of fuel and fluids to give the best results possible without causing unnecessary damage and best performance.

nobody cares if anyone chooses to use whatever they feel like, they are nothing more than recommendations.
Click to expand...

Yes and no. Surprisingly, not at all. It was initially based on the width of the radar target. The targets were 3 miles wide so they wanted a target width between each aircraft. It's now based on perceived air disruption behind certain aircraft.

Yes, but those "recommendations" are based on many, many tests. Were it not for the Magnuson-Moss act I imagine those "recommendations" would be requirements. I bet that if you put engine oil in the transmission the warranty on the transmission would be voided.
 
LS4me, I work with many mechanical engineers, some are much better than others, some are terrible. I agree with swdobbs.
the reality is the recommendations are based upon many years of tests and failure analysis.
ATF fluid is an example of how a fluid is improved and then a TSB is issued for the new fluid.
Mercon has been replaced by Mercon V for added friction additives that help the transmission. owners can stick with the old fluid, or add the new fluid as needed.
 
Reasoning....

BrianDye said:
Some say ATF is better, but I strongly disagree.

PS fluid is meant for the PS PUMP!
ATF is meant for TRANSMISSIONS!

They would make a universal oil that can replace coolant, atf, PS fluid, and wiper fluid now would they? No, each one does its specific job to the best of its abilities :D
Click to expand...

Personal experience here... 1998 BMW 540i required something other than plain PS fluid. Some Gomer at the dealer$hip added plain PS fluid and the rack began to make groaning noises from the seals that were now beginning to swell. Long story short the PS system had to be replaced at dealer expense a few months later.

There is more than simple fluid dynamics at work here. There's water resistance, coefficient of friction, heat resistance, and chemical compatibility with the other soft components such as hoses and seals. Use what the manufacturer recommends and save yourself the doubt and grief.
 
Well since this was brought back up..... Since 2009 (I traded the car the other week) the power steering was fine with Ps fluid.
 
Ford went through a process about a decade ago to consolidate many of the fluids used in the production vehicles making it simpler not only at the assembly lines and dealerships, but also to improve their bottom line costs.

If the Ford / Lincoln / Mercury manual states to use Mercon it is because they had the supplier of the PS pumps, hoses and racks make any change if needed to use the fluid. If they had gone as far as telling those suppliers they wanted to use milk as the hydraulic fluid in the steering system, the suppliers would have changed the components so milk would be correct.

Don't try to outguess the factory engineers and make things mo' bettr. They are not the bean counters you think they are.
 
I try to remember to follow up on my posts, so I guess I dropped the ball on this one.
 
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