Power steering fluid change
 

How much power steering fluid is needed for a change on a '89 300CE? Can I get most of the old fluid out by simply evacuating it from the reservoir or is there a better way? Is the Febi fluid the best choice?

You need one quart. I would suck out the PS fluid from the reservoir while engine is off, either with a vacuum like Mity-Vac or a turkey baster, then fill up with MB PS fluid ($7.50 a quart) to the mark, close the cap, run the engine, turn the steering wheel from left most to right most while engine is running. Repeat all the above 4 times to use up the quart. After that you got 90% new fluid + 10% old fluid mix.

Is the Febi fluid okay to use instead of the dealer fluid? I believe the Febi is an OEM replacement unless I'm mistaken. When should I change the filter, before or after filling & extracting?

Febi is ok.

filter
 

Also , change the filter.

Power Steering Fluid Change
 

I don't see PS fluid filter for my 1996 E320. Is there one?

Filter
 

On my 1989 300E, you have to suck out the fluid with a turkey baster then take off the center lock nut and remove the plastic center pole. The filter is at the bottom of the reservoir. I fished it out with my instrument panel hook! I knew it was good for something else! The filter should be around $5.

Leave the turkey baster in the kitchen. Get a section of heater hose. Jack the front up, pull the cap off the reservoir, pull the low pressure return hose off the pump and push your temp hose over it and allow to drain into a catch basin. Pull the old filter out. Put a new one in. Get the new gasket for the lid too. Have a helper start the car and start steering left/right lock to lock repeatedly, and quite quickly as you poor from a gallon of ATF (Dexron III) into the reservoir keeping the level up. If it sucks air you'll get froth in the output, dump more / faster to keep froth down. When you've done about 3/4 of the amount, stop the car, put it back together. Takes less than 1/2 hour.

scott is offering the best advice in this thread with one exception, you should not use ATF in the p/s system of the 124 car. Since the time that car was built, ATF went through some drastic changes and will attack the seals and other rubber parts on your p/s system.

Follow scotts method, but use p/s fluid from the auto supply store.

If you're not going to flush the system, changing the filter and replacing only the fluid in the reservoir is just a waste of time.

How much fluid would I need to flush the entire system as opposed to a simply evacuation and refill of the reservoir?

ATF Fluid
 

I heard about using ATF fluid but stuck to PS fluid anyway.

Every time I am working on my 300E (not all that often thankfully) I suck out what is in the reservoir then fill it up with new fluid. I figure eventually the fluid will be quite new.

Re: W210 PS Filter ...
 

my 1997 E320 does not have one but if you look at the parts list, there is one listed. I believe that some early W210's had a different pump that required a filter.

Power Steering Filter
 

Are you sure it is not at the bottom of the reservior? I never knew about mine until I read about it on another post.........