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.