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Discussion Starter · #1 ·
I just drained the old red power steering fluid in my 85 300D, and the new fluid is yellow. Is this also acceptable? Here is the product I used:

STP® - Power Steering Fluid

Please help me quickly so I can close it up :confused:
 

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'09 E350 4-matic sport, '83 240D 4-speed (sold), '77/'78 450SLC (junked), '81 500SLC (junked)
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1984 Mercedes-Benz 300DT; 1980 Mercedes-Benz 300SD
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I've read several posts about using just regular ATF (yes, automatic transmission fluid), so thats what I used after changing my power steering filter myself.



torkq
 

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1999 SLK 230 - Firemist Metallic (548) 1983 300D TurboDiesel - Deep Blue (900)
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I believe the base fluid is Mineral oil, to which various additives are...well... added. So I think it all starts off as almost clear to light yellowish fluid. Then it is Dyed to be able to identify it. I imagine, but don't know for certain, that Power Steering fluid is traditionaly Dyed to a Red to distinguish it from other fluids that might leak. So it stands to reason that someone might decide to Dye it a different color than Red sometimes. For mainly marketing purposes I would imagine. Might want to ask STP if this is the case. I do know that many here have advocated both PS fluid or ATF in these as being fine.
 

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Discussion Starter · #5 ·
Well, I thought it was acceptable so I filled it up and closed everything up. I imagine that since I didn't flush the system, I only replaced part of the fluid. When finished, I started the car and turned the steering all the way to the right, then all the way to the left. Check the fluid again, and it was the same dark color as before.
 

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1979 280CE
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Regukar PS fluid is clear/yellowish. MB says to use Dextron III ATF in the PS pump.
 

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81' 300SD, 82' 300D
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Today's ATF contains more additives than the ATF of the 70s and 80s. Modern ATF can weaken seals in the power steering system and cause leaks. Just use some generic over the counter power steering fluid, or if you want to splurge, get the MB power steering fluid.
 

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85 300D
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Well the modern ATF I'm using hasn't destroyed anything yet in 5k miles...might just be better than some GENERIC fluid.

Kinda thinking of switching to Marvel Mystery Oil......;):eek:
 

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1984 Mercedes-Benz 300DT; 1980 Mercedes-Benz 300SD
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Thought that Marvel stuff was ATF... just relabled and over priced?
 

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1959 220S cabriolet, 1983 240D original owner, 1999 E300 turbo diesel, 1988 560SL, 2003 SLK320
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Today's ATF contains more additives than the ATF of the 70s and 80s. Modern ATF can weaken seals in the power steering system and cause leaks. Just use some generic over the counter power steering fluid, or if you want to splurge, get the MB power steering fluid.
I'm on a number of the same forums you are on and I have also seen those reports about how today's modern ATF is no longer a good choice for your power steering system. I have been using ATF in my 240D since 1982 and it has never been an issue. I'd sure like to see some actual scientific reports on why the newer ATF formulas are not good. All that I've ever seen are reports from individuals who have said that after adding modern ATF they developed a leak or a problem. Maybe their systems were ready to fail anyway and using the newer ATF had nothing to do with it. A handful of personal experiences like that certainly isn't scientific. Have you ever seen anything that supports the claim of those who say not to use the new ATF?

Thanks.

Len
 
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