ATF instead of power steering fluid?
 

This is for my 1991 300E W124:

I read on some threads it is acceptable to use ATF instead of power steering fluid in the power steering reservoir, but opinions are varied.

I'm about 3 miles from a store where I can get generic power steering fluid - should I risk taking the 300E with a low power steering level to the store or can I just top off with ATF that I have right here now at home?

By low, I mean, the springs are showing on the bottom (should be covered) and about 4 oz in the reservoir.

I'm planning to do a flush in the next few weeks with the proper power steering fluid (probably have to order).

I've used ATF in place of power steering fluid with no ill effects. I think the main difference is cold viscosity. You're going to replace it soon, anyway.

Thanks, Mxfrank, for your quick reqply.

We don't have cold weather here (Hawaii), and yes, I plan to flush with the approved MB fluid soon.

In the meantime, I need to watch the levels, and check for leaks.

No sense in flushing if leaks are going on, correct?;)

If leaks are going on, you are constantly flushing. But it would be a good idea to change filters.

Thanks for the reminder to order new filters, too.

EDIT: Now I recall (a few weeks ago) seeing some drops of *something* on the driveway - checked underneath and could not pinpoint the source to the leak.

The wetness was running along some of the lines that have the "springs" wrapped around them, close to the front.

I decided to take a closer look at it at the time of the next oil change (this week).

So maybe I will be adding some new seals and/or rings for the pump to my order.

In any event, the atf bottle is in the trunk if additional is needed.

Those would be transmission lines. If they are wet, they need to be replaced.

I checked the transmission fluid level, and it looked full.

MB did fill these car steerings with ATF, dexron II to be exact. No issue in using dexron III on there. Be wary that it will permanently tint the system red.

You can use generic PSF, but it will be thicker to pump when cold. Orielly's sell a PSF which is close to ATF viscosity - its called masterpro PSF.

The steering oil you buy from mercedes benz is actually ATF DII. its also sold by LubroMoly in 1 liter packaging, Its most probably undyed ATF.

Everything I have read recently says to NOT use ATF in the power steering system. It will work but additives in the ATF will cause premature wear to the steering box. This is why W123 and earlier steering gears wear out so quickly. I have a 190D with 320k miles with much less steering play than a 240D with 140K miles. Use Mercedes spec power steering fluid.

Using ATF short term is fine, just don't use it long term.

The photos I was trying to post show NEW brighter red drops!
Same area, along the hose that is spiral bound.

You can order that hose here but any oil rated hose of the right ID would work. I think NAPA has the correct fluid. I can message you a good place to get the fluid for cheap online if you want.

Sorry chap - I don't think this is correct.

As Zulfiqar stated =>


Look at the approved fluids lists - look at the FSM - look in the maintenance manual => all ATF for W114/5/6 W126 W124 W201 models. After that I don't know what happened - never owned anything that new before!

ATF is not power steering fluid and in you workshop manual it said just this . And not to use it, as its not the same.

I think the only early car that required special fluid was the 124 statuon wagon w/SLS. These cars required a particular hydraulic oil,which has specific cold viscosity characteristics. Beginning with W210, a synthetic hydraulic oil was used. AFAIK, others are fine with ATF. I run ATF or magic MB oil interchangeably. If single data points mean anything, my 190d has gone 377k miles without pump or steering box problems.

The SLS cars, 4matic (Styre-Puch system), and ASC diesels through the mid-90s have a separate chamber/system for hydraulics (dual pump) which takes a special FEBI oil (mineral oil?). The power steering on these cars is the same fluid as non-SLS etc. cars.

I haven't really seen what Mercedes says, when I looked last night, their website was down, but the various threads I read when I did my power steering fluid suggested not to use the modern Dextron stuff because of additional additives for the transmission clutches. Our favorite youtube mechanic Kent just posted a video yesterday about the same issue. I just use Mercedes or Febi power steering fluid because that's what those threads have suggested. Here's one such thread:

http://www.peachparts.com/shopforum/tech-help/26578-dexron-ok-power-steering.html

the steering uses this oil for hydraulic motive and the reason ATF is specified is that power steering fluid does not follow any performance specification.

This clause opens a can of worms. the generic power clear/amber power steering fluid you buy from stores is nothing more than ISO46 oil, ATF has defined standards - and mercedes benz chose that because it works perfectly and can be understood easily even at the african trading post in the sahara and also understood at autozone and works like prescribed.

When MB went to the modern super low visosity pentosin oil - they only did so to up the fuel economy numbers and also deem it filled for life (filled for life is very welcome by accountants and lease owners alike). A lot of older BMWs using that are now on ATF fill and some are even on ISO32 hydraulic oil without issues.

Toyota are also in the same boat as mercedes benz when it comes to PSF, the original fill is an amber colored liquid which smells like motor oil, the cap says dexron ATF. If you want to buy replacement fluid they sell you their usual red atf

I would suggest look up the data sheet of the lubro moly lenkgetriebe oil, - it says its equal ATF DII (GM dropped licensing) - but also says its amber.

I'll check with NAPA first to see if they have it; online might be cheaper, but once the shipping gets added, it might be substantially more than NAPA.

EDIT: Still trying to post pictures, no luck.

I found this out, it is for the old type W124 like i have. I only use Mercedes Benz fluids in engine gearbox and power steering . Just sorted it out ... The workshop manual said to use special fluid as the cars are 4x4 dampers and they run off the same system and fluid has the pas pump.. So all are right to use atf.

The special fluid is for the SLS (suspension system, or ASR locking diff (diesel only in US), or 4matic all-wheel-drive (gas only in US), not for power steering. Power steering has a can on top of the PS pump, the hydraulic fluid goes into a plastic tank in the engine bay.

Stretch - Those specs say to use ATF Type A Suffix A for our power steering. Are those out of an old owner's manual? MB Recommended fluids are here (but site is currently down). PS fluids were hidden under ATFs last time I looked.

Problem we have is that Type A Suffix A ATF to the original specs is virtually unobtainable here. Current ATFs that claim to meet the old GM Dex II & III are not the same as Type A but also apparently not the same as even they were back when cars were built.

Power steering fluids can also no doubt vary a lot. Some are dino, some synthetic and they say not to mix. They do claim to have additives that reduce steering box wear and reduce seal leakage.

Could another factor in different specs be the change to rack & pinion on modern cars?

We had a long discussion about PS fluids on BW 107 forum, but no clear resolution except perhaps that Dextron II/III type ATF will work, but steering box may wear out or leak prematurely.]That is what Kent at mercedes source said and it started the BW discussion.

For my 85 and 72, I usually use generic Prestone Power steering fluid just because it is readily available here.- They have many types (just to confuse us) including one for Mercedes/BMW etc that is probably synthetic like the MB fluid and perhaps better suited for later cars. I assume our cars need same as early American cars from back then so I buy the basic type.

One of these days, we will get the definitive answer on this question - but we are not there yet!

the dexron II III friction modifiers are for slippage on the clutch materials. the steering will never have any use of them.

Our old cars can use generic clear prestone/walmart/etc power steering fluid in them too - its basic hydraulic oil but is thicker at low temperature, ATF on the other hand is usually thinner than regular hydraulic oil when cold but is pretty much the same as hydraulic oil at full operating temperature.

If you claim not to find type A fluid - then type F is readily available everyday, very similar blending.

I too was once quite confused in this - but eventually just read on the material sheets and followed them - and add to the point that outside of USA you cannot find generic power steering fluid easily (GM spec etc sold on shelves in USA). I can bet you that the entire moroccan fleet of W123 were not using any "lenkgetreibe" oil or fancy power steering fluid. All of them would be sporting blood red ATF.

NAPA have it usually. it comes in a 1 litre bottle. Some toyota owners also buy that to keep the "amber" color in the steering system.

MAG1 has a PSF that they claim to work on anything (including Honda), its characteristics really mimic that of ATF - except this oil is undyed and has something in it that promotes rapid air expulsion.

Hmmm happened to come by this thread and started reading the replies and I too thought that I read that ATF was ok in the PSP, even in the Haynes manual it states that ATF (Dex II) can be used as well as a MB service manual. However I just resealed my PSP a month or so ago and I have noticed that it is leaking. So I thought I did something wrong and took it apart again and resealed with new seals. Same issue. I went and bought another pump at a junk yard and cleaned it up and fox the seals on that and it's still leaking. I am running ATF DEX II in my PSP. I went and got my ownersowner's manual and it doesn't state anywhere in the manual or on the approved fluids to use ATF in the PSP. It says to use MB power steering fluid 000 989 88 03

I am looking at a W126 OM that says "Automatic transmission fluid for power steering 1" and the foot note 1 says " any MERCEDES-BENZ service station will advise you on recommended brands." Noting about Type A, Type F dex anything. Hard to believe that any ATF produced 30 years later isn't good enough :) Add some stop leak if you have a problem?

ATF makes for a spectacular car fire.

The ATF produced 30 years later isn't the same ATF produced now. It's not made for steering boxes.

Use power steering fluid.

its seems to be quite confusing - Im assuming folks are wanting to put in the clear PSF from mcparts stores, it will work too.

If you guys want a bottle of very good ATF that says "power steering fluid" right on it then buy a quart of Ford motorcraft mercon V, it literally claims Automatic transmission and power steering fluid on it.

white phosphorous on the seats makes the best car fire.. second to gasoline. ATF is a bit lazy in ignition.

I have used brake fluid to top off power steering,has not hurt anything in 15 years,I was told it can actually stop leaks.

What would be the point in using a fluid that isn't even close?

He enjoys sin :D

Interesting concept, misguided/irrelevant as it may be. That same OM says "Automatic transmission fluid for Automatic transmission 1" regards what to stuff into the trans. So if it s good enough for your trans today ...

@Graham

Sorry chap=> Peach parts + oil thread + US of A election year has me "banging out" of this thread!

No problem :)

By the way, as posted in other thread, when I asked, Prestone told me that if car spec says to use ATF Type A Suffix A (as Stretch's OM did), then use their standard Power Steering Fluid (not the Euro or other types)

Power Steering Fluids | Prestone®

Just talked to my oil supplier they laughed and said the spec for that fluid has not changed in 15 years and no one is testing for performance gains in that dinosaur oil. No company is going to spend money to test something that is not in any new car anymore.

New car oils are changing all the time but the old ones will stay the same.

Just an update: Used a turkey baster to take out the red ATF I put in the other day, and refilled the reservoir with the Prestone ps fluid + stop leak. Not going to use the special MB type till I determine where the leak is, and fix it, of course.

That's the whole point. ATFs to those original specs (Type A Suffix A), especially those that are approved by MB are no longer readily available in NA.

PS: I am going to take Stretch's advice and keep out of such discussions from here on :)

Update: Found the leak to be caused by a hose clamp that needed to be tightened up.