While researching available parts for my '80 300SD, I keep coming across a power steering filter. I have never heard of such a filter. I once saw a picture of one. It appears to go in the resevoir. Does anyone know how to change this out? While I am asking, how do you change out the power steering fluid, which apparently is recommended from time to time. Also how much does she hold?

Yes, the filter is in the resevoir. It doesn't take much, as you can really only change what is in the resevoir itself. To get the old fluid out, use a turkey baster or a syringe that you can get for free at the pharmacy counter at the grocery store. Tell them it is for measuring your kid's medicine. If you are real anal, you can suck all the old fluid out, fill it, and repeat the process a few times after running it for a while to change out a larger percentage of the fluid.

I was wondering the same thing. The filter is just sitting at the bottom of the reservoir? My fluid is clear/yellow, so I guess that is power steering fluid and not Dexron ATF which is what my manual says to use in the '79 300SD?

Clear/yellow!?? I was told by my mechanic to use ATF which is red of course. Maybe there are brands out there that are not tinted red. I don't know.

Thanks for the replies. So the filter just sits at the bottom of the resevoir? Any ideas on how much fluid I should buy? My car did not have an owner's manual in it when I bought it, so I don't know whether to use "power steering" fluid or ATF.

The filter is in the resevoir, just hidden from view. If you open the resevoir top and look in, at what looks like the botten of the resevoir, there are a series of holes - that is the steady plate. Drian off the excess fluid by the previously mentioned techniques, then lift the steady plate. Underneath the plate you will find the filter, and the true bottom of the resevoir.

Replace the filter and steady plate, then fill with fresh fluid. Start the engine, work the wheel stop to stop and top off the system.

Many reccommend ATF, but I prefer power steering fluid. Some AFT additives are not good for the steering system and can result in damage, plus the difference in color, smell and taste (hmmmmm, hmmm)help pin point where the spots on the garage floor came from.

can you mix the two fluids?

does anyone know how often this filter is supposed to be changed and how much fluid does the resevoir take?

Patsy,

Not sure about compatability of the two fluids. Personally, I would try to drain as much ATF out as possible, then flush with clean steering fluid, and run only steering fluid from then on.

Rick,

I don't know what the filter change interval is for the steering. An empty system will take nearly two quarts of fluid, an empty resevoir about 2/3 to 3/4 quart (at least on my 108, which is fitted with resevoir #116 460 01 83).

I believe the rule is:

- Use MB power steering fluid if vehicle is equipped with a serpentine belt

- Use ATF is vehicle is equipped with multiple belts

Maybe one of the pros on this site can verify this.


Regards,

Mike Murrell
'91 300-SEL