I just finished switching out my PS pump and realized that the PO had run ATF and I just bought PS fluid. Are they compatible or do I need to flush my system before running the PS fluid or should I just get some atf and run that? Dex 3?

__________________
1981 240D 143k 4 spd manual -SOLD

2004 VW Jetta TDI 5 speed 300k -still driven daily

there are quite a few threads on this, Whunter has a complete list of what is safe to use.

I run type F atf. Others will say nothing but PS fluid off the shelf is to be used.

Some forms of atf are bad for the seals, some will say they have been running atf for years cuz thats what there grandpappy had done.

__________________

Or maybe they read their owners manual.

The additives used nowadays - as described Whunter and his oil specialist- are much different than the additives of the time of copyright for that manual. There are still some types of atf that meet much older standards - ie.. less crap, perhaps?

__________________

Ive been running "Amsoil" synthetic ATF, no problems over the past 5 or 6 years, I spoz the system should be flushed out when switching to P/S fliud, but I wouldn't think a 'little" mixing would hurt??

__________________


1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

Just last week, I removed the PS pump to repair leak (large O-rings). I did extensive research on this site and found that the general consensus is to use just plain old off the shelf power steering fluid, as it is most closely like the original ATF recommended back in the 70's and 80's. I use Valvoline (clear) PS fluid. A smaller group recommends Type F transmission fluid, as being close to what was originally specified. Lesser numbers stay with ATF, either regular or synthetic, since the manual specifies ATF. Myself, I relied on the fairly consistent recommendations of very knowledgeable and reliable long standing contributors to this site who recommend regular clear power steering fluid.

You don't have to worry about incompatibility between ATF and PS fluid....they are compatible...just flush away. I flushed with two gallons...yes two gallons of PS fluid, trying to get the red stuff out (I previously ran Redline Synth. ATF), wanting to see pure clear fluid in there. AFter driving for a week, I still saw a pink color...I knew this was just fine, but being the nut that I am, I flushed it again with yet another gallon of Valvoline PS fluid.

Yes, I also replaced the filter in the pump with a new one.

In my case, I don't belive the redline ATF caused the large o-ring seals to leak...instead, it was the build up of corrosion of the alloy pump housing around the exposed portion of the o ring around the edges of the back plate...the corrosion (aluminum oxide?) pushed/distorted the o ring causing the leak. I brushed this groove out, cleaned with some PS fluid, wet the new o rings with PS fluid, cleaned the contact edges of the back plate with fine steel wool, and put back together...now not a single leak.

Good Luck,

Mark

__________________
1984 300TD Wagon, 407,800 mi (current daily driver)
1985 300DT Sedan, 330,000 mi (gone to that great autobahn in the sky)

I'd suggest runing a search, there's very long threads about this topic.

On my car I just ran PS fluid through the system and keept flushing it until it stayed clear (the PS fluid I chose was clear). The PS fluid is so cheap this wasn't a problem.

-Jason

__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

So many cars go to the junkyard with the factory original PS fluid still in them (black with age, of course) that any change has to be for the good, even to ATF. That said, flushing the system with a decent brand of PS fluid (I bought mine at a local NAPA store) is probably best. I don't think it's necessary to use a Mercedes PS fluid but since it gets changed so infrequently it probably won't break you.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .343,000 miles Wife's car
2005 E320 CDI . . 148,000 miles My car
Santa Rosa population 177,300 (2026 projected)
Total. . . . . . . . . . . . 668,300
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

I thought the arguement was that ATF now isn't what ATF was in 1970?

-J

see post #6

__________________

Why is it that the changes in the formulation only have a negative affect on power steering systems and not on transmissions?

Has MB ever issued a Service Bulletin, etc., which addresses this issue?