Needed to top up my 85 300D's PS fluid, but could not find any amongst my supplies.

Drove down to autoparts store. They had several types from different manufacturers. Prestone had two types:

European and Domestic (Ford, GM, Chrysler but would work on most foreign cars, the bottle says).

The European said it was 100% synthetic. Domestic didn't say.

Seeing I wasn't going to drain and flush (fluid looked clean), I wasn't sure which one to buy, so went with the domestic one, since I can't recall ever using synthetic before.

When our car was made, I think it called for Dextron in PS. I know I have bought PS fluid in past, but can't recall for which car same with filter. I think I changed it a little while back, but need to make sure it was on 300D and not SL.

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

I bought a bottle from the auto haus.....was more then enough for a 2 fills.....thought it would be cool to have Mercedes brand fluid in the power steering....but to my dismay my fluid is now as black as it was before I flushed it......if you have a nice clean system I would spring for it.....otherwise I have always used the generic power steering fluid.....atf is what is recommended but I have heard it can cause a leak....

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I have always used ATF, Dextron not the Ford variation.

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Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22

At the time of the release of the vehicle's documentation ATF was specified for the power steering.

If you don't know about it, this might help =>

There's a bolt on the steering box that is used to center it during installation. If you undo it and turn the wheel hard lock left all of the oil in the system drains out nicely.

http://www.peachparts.com/shopforum/2768406-post5.html

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

^^^^ I have to look again, but I didn't see a bolt on the bottom of my gear box when I drained my fluid....I will look when I clean the ground strap....

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It's something like a 13mm IIRC. And in my experience most of them were painted red, although probably not so much red is visible after being underneath the car for so long.

And don't lose the copper washer on it. They will leak without it.

Credit to Stretch:

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Onus probandi incumbit ei qui dicit, non ei qui negat

I recondition w123/w126/w124/w140/r107/r129/ steering boxes!


1984 300D "Elsa" odo reset 6/2011 147k
1983 300TD "Mitzi" ~268k OM603 powered
1995 E300 "Adelheid" 262k [Sold]

Zach,
The reason I use PS fluid, is that I read that ATFs have changed since these cars were built and that some of the additives needed to reduce wear in transmissions can have negative effects in PS systems.

I don't really know, but a bottle of PS steering fluid costs about same as one of ATF. But then they go and confuse me with Euro vs Domestic and Synthetic vs whatever as described in first post

At the moment, I just topped up. May flush later but other work is piling up. Brakes on W210 need attention so newly "restored" 300D needs to be back on road
Graham

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

My personal preference is for plain PS fluid, synthetic or not, so long as it is colorless. That makes it much easier to see if it's getting dirty.

For my cars, MB doesn't specify a change interval, just "check and top up." For example, the 1996 E300, as purchased by me in 2007, had NEVER in 249,000 miles had its PS fluid changed (I have the service records since Day One). The fluid was BLACK with age and mechanics had reported impending pump failure to the PO. (Symptom: failure to generate pressure at parking lot speeds, when you really need the assistance.)

After the fluid was changed several times, most of the problem went away. Now at 291,000 miles the pump is still working. I suspect many cars go to the junkyard with the factory fill of PS fluid so anyone who changes their fluid at all is ahead of the game.

Jeremy

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

Honestly, I cannot imagine at the moment a part in the PS system that would be "damaged" by wear additives found in ATF.

In the PS system there's a pump to pressurize the system. Same thing is found in an automatic transmission.

In the PS system there's moving gears which carry load/torque. Same thing is found in an automatic transmission.

Same thing with pressurized lines.

Same thing with a filter, heat, etc.

I've been inside enough boxes to notice that the only things which seem to degrade these boxes is lack of fluid or dirty fluid.

If you ask me, use ATF. Doesn't matter the kind or the color. Just don't let it get dirty.

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Onus probandi incumbit ei qui dicit, non ei qui negat

I recondition w123/w126/w124/w140/r107/r129/ steering boxes!


1984 300D "Elsa" odo reset 6/2011 147k
1983 300TD "Mitzi" ~268k OM603 powered
1995 E300 "Adelheid" 262k [Sold]

This is what MB currently recommend for some recent models (G,M,GL,R class). They don't seem to cover earlier models so far as PS is concerned unless this information is elsewhere. To add to confusions, Kent on MercedesSauce offers a kit that includes PS fluid, which he says is only good for 1986-1995 models. Later models are covered by MB on the Startek site, but nothing found so far for earlier cars.

MB Power Steering Fluid MB Part No. BQ 1 46 0001
or
Approved Dexron III Automatic Transmission Fluid (Note 1)
Castrol Dexron-III/Mercon ATF F-30341
Castrol Transmax M-22257/22096
Chevron ATF Dexron III F-30108/30159
Citgo Multi-Purpose ATF D-21571
Exxon Superflo ATF Dexron III F-30111
Havoline ATF Mercon/Dexron-III F-30321
Texaco ATF Mercon/Dexron-III F-30321
Pennzoil ATF D-22413/F-30110
Quaker State Dexron-III/Mercon F30161
Sunoco ATF Dexron-III/Mercon F-30176
Unocal Multi-Purpose ATF D-22413/22431
Valvoline ATF Type D

(Note 1) Please see your Mercedes-Benz Center regarding applications. Do not use in 722.6 or 722.9 transmission!

Interestingly, GM no longer license their Dexron II and III technology and those products are no longer sold as such. They say that the name should not even be used, but obviously there are many knock-offs. They now use Dexron VI in transmissions, but say not to use it in PS.

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

Just drained the fluid from the gear box, it is a 12 mm nut if anyone does theirs....I need a new filter again but opted to just replace the fluid since I had extra.....funny my fluid went in clear but it is red....maybe 5 more flushes and it will be clear

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