Power Steering Oil, what type? - PeachParts Mercedes-Benz Forum

KCM · #1 12-13-2004, 10:59 AM

When changing the power steering oil in a W123, what is the correct type to use? I believe the owner's manual says automatic transmission fluid, but ATF has changed since the early '80's. Should I use Dexron, Type A, Type F, or something else? Dexron looks too thin to me.

Thanks in advance.

MikeTangas · #2 12-13-2004, 11:06 AM

Regular old PepBoysAutoZoneMcParts power steering fluid will work fine in your 123.

dmorrison · #3 12-13-2004, 11:15 AM

Do a Search
This was discussed quite a bit.
You probably have dextron transmission fluid in the car now. This is approved by Mercedes and 90% of the people use it.
However the discussion was posted as to the changes in tranny fluid over the last 20 years and it might be better to use power steering fluid.
My concern would be changing the fluid might produce leaking seals in these 20 year old cars.

Dave

P.E.Haiges · #4 12-13-2004, 11:35 AM

KCM,

There have been a couple of reports here that after the power steering fluid was replaced with auto trans fluid (ATF) in the power steering system, the pump seals started to leak.

Therefore I would not recommend putting ATF in the powering steering system. I wouldn't recommend putting ATF in the engine either. ATF is made for auto transmissions and that is what it is used for.

P E H

Diesel Diane · #5 12-13-2004, 11:46 AM

The owners manual for my '82 300D specifically calls for ATF in the power steering system. That's all I have ever used. Never had a problem.

84300DT · #6 12-13-2004, 12:29 PM

in the fwiw dept., had an A2 VW that could also use ATF in the power steering "if necessary" according to VW. the thing leaked like a sieve so ATF was cheaper to keep putting in....

kmaysob · #7 12-13-2004, 01:54 PM

order power steering fluid from fastlane

Wasuchi · #8 12-13-2004, 02:04 PM

I put the Castrol "synthetic" ATF in mine last year (about 20k miles ago) and it doesn't leak a drop. I think it's another of those things that it'll leak worse if there is a pre-existing leak or damaged seal but if everything is fine it won't cause a problem.

That said, I would use the Valvoline semi-synthetic powersteering fluid if I did it again. I've heard nothing but good things about that stuff and it's pretty easy to find.

#9 12-13-2004, 02:16 PM

Your 20 year old owners manual indicated ATF, but they had no crystal ball when writing it so they did not know that ATF was going to go through such drastic changes.

MODERN ATF is bad for the seals. If you INSIST on using ATF, find some type A somewhere. The best thing to do is to use power steering fluid from the auto supply just as Mike Tangas suggested.

I have personally had seal failure after using Dexron, and I read in Popular Mechanix about 10 years or so ago about the changing formula of ATF and how it effects power steering systems.

To change it is best to flush the system by disconnecting the return line from the reservoir and laying it in a drain pan, then pour some P/S fluid through the system while an assistant turns the steering wheel back and forth. About 2 quarts will flush it properly. Then reconnect the return line, fill and turn the steering wheel lock to lock several times to bleed. Replace the filter while you're at it. This is the method that is actually a question on the ASE test.

Merry Christmas,

Hatterasguy · #10 12-13-2004, 02:33 PM

Larry is right power steering fluid is cheap don't use atf. I bought some from the dealer because I didn't want to make a special trip to the parts store. $10 for a quart of the offical MB stuff.

Scott98 · #11 12-13-2004, 02:47 PM

I've been meaning to change the fluid on my car for a long time. I didn't realize it was this easy to do. One question though: Where is the filter located? Is it inside the housing? Not to start a war here in case this is a hot topic, but should I use the MB fluid or will any do?

Thanks,

Scott

boneheaddoctor · #12 12-13-2004, 02:50 PM

Quote:

Originally Posted by Scott98

I've been meaning to change the fluid on my car for a long time. I didn't realize it was this easy to do. One question though: Where is the filter located? Is it inside the housing? Not to start a war here in case this is a hot topic, but should I use the MB fluid or will any do?

Thanks,

Scott

Under the cap it slides down on the stud the lid is screwed on with.

#13 12-13-2004, 02:53 PM

Any old power steering fluid from the parts or discount store.

Merry Christmas,

oldnavy · #14 12-13-2004, 02:59 PM

Quote:

Originally Posted by LarryBible

Your 20 year old owners manual indicated ATF, but they had no crystal ball when writing it so they did not know that ATF was going to go through such drastic changes.

MODERN ATF is bad for the seals. If you INSIST on using ATF, find some type A somewhere. The best thing to do is to use power steering fluid from the auto supply just as Mike Tangas suggested.

I have personally had seal failure after using Dexron, and I read in Popular Mechanix about 10 years or so ago about the changing formula of ATF and how it effects power steering systems.

To change it is best to flush the system by disconnecting the return line from the reservoir and laying it in a drain pan, then pour some P/S fluid through the system while an assistant turns the steering wheel back and forth. About 2 quarts will flush it properly. Then reconnect the return line, fill and turn the steering wheel lock to lock several times to bleed. Replace the filter while you're at it. This is the method that is actually a question on the ASE test.

Merry Christmas,

I used ATF in my PS had it started leaking like crazy, I flushed it like Larry said and used a "stop leak" type of PSF and no leaks 6 months later.

boneheaddoctor · #15 12-13-2004, 03:02 PM

shortly after I bought mine I noticed a growl when wheels were turned, I put a bottle of PS fluid I had in my saturn...that was before I heard this called for an early form of ATF......So I have had not problems......