ATF in power steering system question

[Johnny248]

So, many manufacturers spec using some sort of ATF as an accepted or recommend fluid for power steering systems. Some other vehicles spec actual "power steering fluid" , and other even use some "special" type of fluid such as Honda, or some of the Euro cars that call for a Ch-fluid.

I have replaced fluid in systems that used older style "power steering fluid" with ATF and never had any problems. And I think some even recommend using ATF now even in order vehicles that didn't use ATF.

So today while bored, I was on Lubegard's site looking at their products, and in the info regarding their Power Steering fluid, I cut this statement out


"Power steering fluid is not interchangeable with automatic transmission fluid (ATF) because ATF does not have the anti-wear protection or shear stability needed to protect the power steering pump."

Where does this come from? If ATF does not protect power steering pumps, why are OEM's using it?

Is this supposed to be directed for a vehxole that calls for the old style, brown/yellow power steering fluids that Chryser,GM, and others used to use in their older vehicles?

Just trying to make sure I'm not missing something here with P/S fluid and ATF.

 

[Chris142]

My jeeps PS pump growled with atf.switched back to PS fluid and all is well

 

[crazyoildude]

My 96 dodge caravan has growled sice i changed the rotted lines and used max life atf..I will be changing to mopar power steering fluid this week to see if it quiets down a bit.

 

[Kira]

Hello, I sure don't have the whole story but I think I can shed some light.

Power steering pump construction has developed.
Today, small rotating vanes (say 15mm high X 12mm wide) live freely in cuts in a disc. They can move in and out of their respective cut.
The resulting shape is a water wheel which turns in a contoured housing. It's mechanically simplified peristalsis.
These teeny-weeny chips of metal are sensitive and require lighter, less waxy fluid.

PERSONAL INVOLVEMENT: Knowledgeable people said synthetic P/S fluid was necessary in my '99 Volvo V70.
3 dealerships I asked used Castrol ATF. The owner's manual specced ATF.
The previous owner of my '99 had a monkey install ATF and it destroyed the pump. A complete flush with CHF-11S provided a 40,000 mile reprieve.

My 2002 was said to require synthetic. The owner's manual still cited ATF. The previous owner of my '02 had a monkey install ATF and it destroyed the pump. A complete flush with CHF-11S provided a 40,000 mile reprieve.

The PS pump from a junkyard '01 dripped pale green (CHF-11S) synthetic when I harvested it.

The manual stayed uncorrected for years.

You can use synthetic in any P/S pump. Many have said the seals in modern systems require a synthetic.

FYI: All CHF means is Central Hydraulic Fluid.
A parts dept. counterman at a Honda dealership said Hondas P/S fluid is simply blue synthetic.

I have CHF-11S for my Volvo and the family's Saabs.
I buy Honda P/S fluid for my brother's Odyssey and the neighbor's Accord.

Cheap enough premium to keep it off my mind. I'm sure the Pentosin CHF-11S would be fine in everything. Kira

 

[dlundblad]

Originally Posted By: Kira
Hello, I sure don't have the whole story but I think I can shed some light.

Power steering pump construction has developed.
Today, small rotating vanes (say 15mm high X 12mm wide) live freely in cuts in a disc. They can move in and out of their respective cut.
The resulting shape is a water wheel which turns in a contoured housing. It's mechanically simplified peristalsis.
These teeny-weeny chips of metal are sensitive and require lighter, less waxy fluid.

PERSONAL INVOLVEMENT: Knowledgeable people said synthetic P/S fluid was necessary in my '99 Volvo V70.
3 dealerships I asked used Castrol ATF. The owner's manual specced ATF.
The previous owner of my '99 had a monkey install ATF and it destroyed the pump. A complete flush with CHF-11S provided a 40,000 mile reprieve.

My 2002 was said to require synthetic. The owner's manual still cited ATF. The previous owner of my '02 had a monkey install ATF and it destroyed the pump. A complete flush with CHF-11S provided a 40,000 mile reprieve.

The PS pump from a junkyard '01 dripped pale green (CHF-11S) synthetic when I harvested it.

The manual stayed uncorrected for years.

You can use synthetic in any P/S pump. Many have said the seals in modern systems require a synthetic.

FYI: All CHF means is Central Hydraulic Fluid.
A parts dept. counterman at a Honda dealership said Hondas P/S fluid is simply blue synthetic.

I have CHF-11S for my Volvo and the family's Saabs.
I buy Honda P/S fluid for my brother's Odyssey and the neighbor's Accord.

Cheap enough premium to keep it off my mind. I'm sure the Pentosin CHF-11S would be fine in everything. Kira



Take her word for it. I am the monkey that almost put Maxlife ATF in my GF's Volvo last month. CHF-11S all the way for her car.

That being said, I have seen that older domestic vehicles normally want the PS fluid. Some Jeeps take a special fluid since the PS pump runs the hydraulic cooling fan, but to my knowledge anything else Jeep at least pre bale out and older uses conventional fluid with the exception of the different cooling fan.

I had a friend that had a Neon SRT4 that was of the same vintage of my Jeep that wanted ATF in the PS system though.

Research is the best thing you can do though if you are not 100% sure.

 

[slacktide_bitog]

Most people never change PS fluid anyway, so really the only times you would need to add anything is if it's leaking, or if you're replacing something and need to drain the fluid anyway.

Most of the power steering systems other than Honda and the Euros can use ATF. In fact, the factory fill power steering fluid may very well be un-dyed ATF (again, except Honda and the ones that call for the green CHF)

Ford used Type F in their power steering systems until the mid/late 90s.

Supposedly the CHF is similar to Honda's fluid. Also, Autozone seems to have the best price for CHF.

 

[Leo99]

My Toyotas specify ATF on the PS cap and not the fancy T-IV they put in the tranny. I'm still on the factory fill. I don't see a point to change it. The ATF has been doing a fine job so far.

 

[earlyre]

never changed any of it out, but i can say for certain, That both my previous car, and my current car call for the same formulation Atf in the PS system as the transmission.
Atf+4 in my Neon, Mercon V in my Sable.

 

[Colt45ws]

Its maker specific. Im not certain why some vehicles will fail a PS pump with ATF. It may be a viscosity problem with ATF vs the fluid the system was designed for.
They are fairly simple pumps. There isnt a significant amount of high-load going on to require a high amount of anti-wear. An ATF is at least as shear stable as any other fluid and if its a modern spec is much more so, due to the clutch action of a transmission shearing fluid so one of the whole points is to avoid that.
The vehicles it is approved for is likely a cost saving measure on the assembly line not having to stock an additional fluid.\

Heres what I think; if your car requires a specific PS fluid, use that AND order the OE fluid. I certainly wouldnt use generic 'PS Fluid' from a auto parts store; there is no spec on those bottles, so how are they formulated? What is it made for?

 

[Lolvoguy]

Amsoil equivalent to CHF-11S?

http://www.amsoil.com/shop/by-product/tr.../?code=ARTQT-EA

 

[Garak]

Originally Posted By: Johnny248
So today while bored, I was on Lubegard's site looking at their products, and in the info regarding their Power Steering fluid, I cut this statement out


"Power steering fluid is not interchangeable with automatic transmission fluid (ATF) because ATF does not have the anti-wear protection or shear stability needed to protect the power steering pump."

Infiniti actually calls for Dexron-VI (or Matic J or S) for the power steering, along with Genuine Nissan PSF. The ATF examples are actually indicated as preferred for Canada.

 

[Johnny248]

Interesting. I'm pretty sure Chrysler recommends ATF +4 now even on older vehicles that used PSF.

One thing about the Euros... I've read a good number of people who have had success and good results flushing out their VW/Audi systems with ATF. +4 seems to be the fluid of choice other than the CHF11s fluid. Of course some people swear that ATF is a no-no in those systems, and have alleged blown steering gears, etc. Yet other people have reported the same problems with th CHF11s.

That being said, I was even thinking about flushing out our VW and using +4 or D6 simply because I have a lot of it on hand.

 

[Boss302fan]

Power Steering fluid is really only a Hydraulic fluid.

I usually replace the fluid every 3-4 years and use Redline power steering fluid or Lucas Power Steering Fluid with Conditioners... Both seem to work fantastic in older or new vehicles.

 

[Whitewolf]

It's best to use whatever is recommended. Power steering systems may contain materials that could be a problem if anything other than the approved fluid is used.

 

[MolaKule]

Quote:
Where does this come from? If ATF does not protect power steering pumps, why are OEM's using it?

Is this supposed to be directed for a vehxole that calls for the old style, brown/yellow power steering fluids that Chryser,GM, and others used to use in their older vehicles?

Just trying to make sure I'm not missing something here with P/S fluid and ATF.


Aahhhhmmmm, could it be LubeGard is trying to sell another product?


ATF is usually used in a Power Steering system UNLESS the manufacturer specifies otherwise.

Most ATF has a KV of between 5.9 to 7.5 cSt@100C.

Honda is one of those 'UNLESSE'S.' Some of the Honda Power Steering systems require a fluid that looks like a dedicated MTF with a viscosity of 11.0 cSt.

 

[dlundblad]

Now that you guys say it, I remember seeing a guy use Maxlife in his Mazda B3000's (Ford Ranger) PS system on YouTube.

Originally Posted By: Lolvoguy
Amsoil equivalent to CHF-11S?

http://www.amsoil.com/shop/by-product/tr.../?code=ARTQT-EA

No way would I use that. Pentosin has a European PS fluid that meets the requirements of CHF-11S. I wouldnt mind using it as a top off, but an actual change I'd prefer the real deal.

I claim I am not a huge universal fluid fan, but I like Maxlife ATF. Go figure.

 

[Lolvoguy]

Originally Posted By: MolaKule
Quote:
Where does this come from? If ATF does not protect power steering pumps, why are OEM's using it?

Is this supposed to be directed for a vehxole that calls for the old style, brown/yellow power steering fluids that Chryser,GM, and others used to use in their older vehicles?

Just trying to make sure I'm not missing something here with P/S fluid and ATF.


Aahhhhmmmm, could it be LubeGard is trying to sell another product?


ATF is usually used in a Power Steering system UNLESS the manufacturer specifies otherwise.

Most ATF has a KV of between 5.9 to 7.5 cSt@100C.

Honda is one of those 'UNLESSE'S.' Some of the Honda Power Steering systems require a fluid that looks like a dedicated MTF with a viscosity of 11.0 cSt.



Similar to the Amsoil product I posted a link for above?

If so, is there a comparable product made by other manufacturers?

 

[Garak]

Originally Posted By: Lolvoguy
Similar to the Amsoil product I posted a link for above?

I believe Bardahl makes a Honda/Acura PSF. As for the CHF 11S, there are other manufacturers besides Pentosin, such as Febi-Bilstein. The OEM VW/Audi stuff actually wasn't terribly priced at a dealer here.

 

[Johnny248]

Looking at CHF11s , MaxLife, +4, and DexVI fluid viscosity

CHF11S
@100 6.0
@40 18.7
VI 313 (wow!)

MaxLife ATF
@100 5.91
@40 28.82
VI 156

Castrol +4
@100 7.5
@40 33
VI 206

Castrol Dex VI
@100 6.1
@40 30.2
VI 148


Looking at these numbers alone, the CHF11s looks like it would pump and flow easier in colder temps, which I would think may or may not improve power steering performance/smoothness in cold temps. Also, the VI is pretty darn high at 313.

This info obvisouly doesn't tell you what additives or other properties may affect performance or wear protection.

It seems like the CHF is really good stuff, but is it overkill in a p/s system? Would it be good to convert an ATF system to CHF11s? Would there be any real issue or damage by converting a CHF system to ATF?

 

[Garak]

That is something that guys like Mola, or perhaps Pentosin themselves, could answer. I'm leaning towards overkill, since I do see -40 and have used all kinds of "lesser" fluids in power steering pumps over the years. I think even turkey baster refreshes are way ahead of what the average person does.