I've been using the MB PSF in my '87 560SL. It's cheap enough for how much you use.
The bigger question is where did the old PSF go?
I just topped up my PSF, but the answer to that bigger question was obviously my garage floor -- post forthcoming.

 

I've been using the MB PSF in my '87 560SL. It's cheap enough for how much you use.
The bigger question is where did the old PSF go?.

I replaced the PS hose(s) 2 years ago, so where has it gone is a good question.
Where are you getting the M-B recommended PSF that you're using?

 

Mercedes originally specified Automatic Transmission Fluid for the Power Steering.
Mercedes Source Kent who does Youtube videos on Mercedes recommends Synthetic.
I just use ordinary non-Synthetic Power Steering fluid.

 

I've discovered the original use of AT fluid for PS, but this issue seems to have been straightened out.
Part of my current problem here, Carl, is whether non-synthetic or synthetic is better, is either choice recommended by M-B for my car, and where can the best choice be purchased?

 

ATF has changed from the time our cars were built. Additives are now different even with Dextrons. Power Steering specific fluids are available that include anti-wear additives. The one I have used for my 98 and earlier cars is Febi 08972. It is not synthetic.

Kent is not clear (to me) in this video on synthetic vs non-synthetic but does say that early cars like ours don't need synthetic. One in video that he sells, is Febi 08972 (white bottle). Apparently meets spec MB 236.3, part number 0009898803. That spec is even the correct one for my 98 W210 and is what I have used. I flushed that car by sucking reservoir out and replacing with fresh fluid, running engine while turning steering back and forth, then repeating 3 or 4 times.

In other videos, Kent recommends synthetic for later models 1986-1995. That would be Febi 06161 (green bottle) that is type CHF11S. https://mercedessource.com/store/1986-1995-synthetic-power-steering-fluid-flush-kit
Interestingly, FEBI do not list an MB spec for that fluid that this meets: https://partsfinder.bilsteingroup.com/en/article/febi/06161 (Mercedes part for 11S is Q1320001 - Probably same as Febi 06161??)

One thing I read somewhere, was that the two types (mineral and synthetic) should not be mixed. Nor should synthetic be mixed with old Dextron. This means making a 100% flush. Not easy to do.

Please feel free to shoot me down - Just what I learned before working on my W210 steering system.

 

ATF has changed from the time our cars were built. Additives are now different even with Dextrons. Power Steering specific fluids are available that include anti-wear additives. The one I have used for my 98 and earlier cars is Febi 08972. It is not synthetic.

Kent is not clear (to me) in this video on synthetic vs non-synthetic but does say that early cars like ours don't need synthetic. One in video that he sells, is Febi 08972 (white bottle). Apparently meets spec MB 236.3, part number 0009898803. That spec is even the correct one for my 98 W210 and is what I have used. I flushed that car by sucking reservoir out and replacing with fresh fluid, running engine while turning steering back and forth, then repeating 3 or 4 times.

In other videos, Kent recommends synthetic for later models 1986-1995. That would be Febi 06161 (green bottle) that is type CHF11S. https://mercedessource.com/store/1986-1995-synthetic-power-steering-fluid-flush-kit
Interestingly, FEBI do not list an MB spec for that fluid that this meets: https://partsfinder.bilsteingroup.com/en/article/febi/06161 (Mercedes part for 11S is Q1320001 - Probably same as Febi 06161??)

One thing I read somewhere, was that the two types (mineral and synthetic) should not be mixed. Nor should synthetic be mixed with old Dextron. This means making a 100% flush. Not easy to do.

Please feel free to shoot me down - Just what I learned before working on my W210 steering system.

Thanks for the video, but Kent is not clear to me either!
What I have discovered that you've referenced above is the Power Steering Fluid Q1320001 that does seem to be M-B recommended for my car...and although it doesn't seem available locally, it does seem available over the net.

 

Is this for a 107? I somehow doubt that Q1320001 is the correct PS fluid. But it could possible be used if the system was flushed and converted to that. MBBevo says that it is intended for

Power steering at outside temperatures below –25 °C: Model 166, 168, 171, 172, 197, 199, 203, 204, 207, 209, 211, 212, 215, 216, 219, 220, 221, 222, 230, 231, 240, 414 Electrohydraulic power steering pump: Model 164 hybrid, 164 Fuel Economy, 251 Hydraulic window lifter: Model 221 with code Z07 (Highest protection) Active Roll Stabilization: Model 166, 292 with code 468 (ACTIVE CURVE SYSTEM)

It can be found at various places on-line as well as, I am sure , at dealer if you ask for the correct type. It seems part number may be 001 989 24 03. Alternatives here:

Mercedes-Benz PENTOSIN Hydraulic System Fluid - CHF 11S - Synthetic Oil for Power Steering (1 Liter) - (MBZ Approval:345.0) Q1320001

But if you need this for a 107, I would think you need the older type spec MB 236.3, part number 0009898803 . In any event, that's what I would use on my cars up to 1998. Even here in Canada, we don't often get to -25C and certainly not for my old cars

 

I found the Part Number: Q1460001 at both European.com and Autohausaz.com

1989 Mercedes-Benz 560SL Base Convertible 107.048 5.6L V8 | Accessories, Oil, Fluids, and Chemicals | Page 1

www.rmeuropean.com

Genuine Mercedes Q1460002 Power Steering Fluid; Standard Non-Synthetic; 1 Quart - Dodge, Freightliner, Mercedes | 0009898803 000989880310 000989880315 97533002001

Maintain smooth steering with Genuine Mercedes Power Steering Fluid Q1460002. This standard non-synthetic, 1-quart fluid is suitable for various Dodge and Mercedes models, ensuring efficient and reliable power steering performance.

www.autohausaz.com

The bottles look different, but they both have the Q1460001 part #

Now I have a couple of other questions:
Is synthetic or non-synthetic the way to go
I've never had the PSF fluid changed or added to, so is it important to know what's already there (can I mix syn w/ non-syn)?
Or, do I need to empty the existing fluid and replace with new (either synthetic or non-syn)?

 

Is synthetic or non-synthetic the way to go
I've never had the PSF fluid changed or added to, so is it important to know what's already there (can I mix syn w/ non-syn)?
Or, do I need to empty the existing fluid and replace with new (either synthetic or non-syn)?

I think those questions have already been answered above. Just use non-syn Q1460001 by MB or Febi You can change it a bit at a time with a turkey baster (do it after Thanksgiving)

 

Thank you to all for helping me to better understand about PSF!

 

I was getting ready to order the Q1460001 that we've discussed, but it occurred to me that I don't really know what kind of fluid is in there at the moment. If I wanted to exchange all of the fluid for new, how many quarts will I need?