Power steering problem - PeachParts Mercedes-Benz Forum

craiggotgame · #1 11-13-2002, 03:26 AM

I have been having some issues with my power steering. Ever since the teperature has been dropping my car has been making some noisy humming sounds whenever I turn the wheel. It is really driving me crazy. It seems like it is fine in the morning when I leave the garage, but after its been outside in the cold all day, it makes these noises on the way home. Anyboby else have anything like this happen to them? Help PLEASE!

janko · #2 11-13-2002, 05:55 AM

did you have an opportunity to check the power steering fluid level?

#3 11-13-2002, 07:07 AM

If the fluid level is okay, it would be a good idea to flush the system.

To do this, place a drain pan underneath the pump area, disconnect the return hose and lower it into the pan to keep from making a mess. Plug the pump port from which you disconnected the return hose and pour in some fresh power steering fluid. Have someone start the engine and turn the wheel back and forth while you pour through two quarts of power steering fluid.

Remove the plug, reconnect the return hose and top off the reservoir. Start the engine and turn the wheel back and forth a couple of times. Top off the reservoir and replace the cap.

You are finished. You can buy power steering fluid at your local auto supply for about $2.50 per quart, making this about a $10 project.

Good luck,

#4 11-13-2002, 08:47 AM

First I Think I would check the belt.. just to be sure its tight and ok..

Next I would remove the power steering fluid that you see when you check it... use some thing to suck it out and change the filter that is at bottom.. It cost just a couple bucks.. just remove the plastic or nut that is holding the spring that you see under the lid.. lift the filter out.. Drop a new one in and replace the oil you removed with new oil... See if that solves the problem.. Lots and lots of power steering pumps have been replaced because of a dirty filter..

In normal service I remove the oil that you see when you check the power steering oil and replace it every other oil change.. That is not a complete change but does keep adding fresh oil.. I change the filter every couple years.. I have never replaced a power steering pump in over 45 years of Mercedes owner ship.. But have replaced the seal..

Ken

#5 11-13-2002, 09:29 AM

Replacing the relatively small amount of fluid in the reservoir will do very little. Replacing the filter is certainly a good idea though.

Flushing the system is a very quick and easy thing to do and can be accomplished easily in less than a half hour. It will not only clean the system, but also replace ALL the fluid in the system.

Good luck,

ronald_m · #6 11-13-2002, 11:33 AM

Same here on my 96' e320 on cold temp. I only hear the humming noise on the first turn of the steering wheel.

Larry,
What do you mean by the plug port?where is the return hose?

#7 11-13-2002, 11:45 AM

What I mean is to plug the hole from which you disconnect the return line. The return line will be the one that has a screw clamp on the hose. The other line is the high pressure line which should be undisturbed.

You can either loosen the screw clamp and pull the hose off of the steel tube, or what I think is easier is to loosen the fitting and put the whole thing in the drain pan. You can then put enough tape around a bolt to plug the hole from which you disconnected the line.

It will be a little cleaner if you suck as much oil as you can from the reservoir before disconnecting the return line. Then you will only have a little oil dribbling down the side of the pump into the drain pan.

Don't get any bright ideas to use solvent. You could easily damage the pump or a seal.

Good luck,

ronald_m · #8 11-13-2002, 03:13 PM

Thanks.

craiggotgame · #9 11-14-2002, 02:12 AM

Thanks you guys are awesome!

ILUVMILS · #10 11-14-2002, 07:13 PM

Hey guys, sorry to be the one to break the news, but there's no P/S filter on craig's car. Just make sure the fluid level is OK. The flush idea sounds like fun but it's not really necessary. Except for the occasional leak, the 210 system is pretty much trouble free. Good luck

Jeremy5848 · #11 11-15-2007, 07:34 PM

In February 2007, the PO complained to his mechanic that his (now my) '96 E300D was occasionally hard to steer at low engine speeds (i.e., parking lot maneuvers). The mechanic recommended replacing the power steering pump for $637.74 parts and labor. The PO chose to live with the problem and in that condition the car came to me. (Yes the PO mentioned it up front.)

I have confirmed the PO's complaint. Occasionally, not always, the steering gets "hard," just as if the pump had stopped making pressurized fluid. I checked the fluid -- it is at the correct level but seems to be very dark, an almost-black dark brown. With my handy turkey baster I sucked out as much fluid as I could (about 3/4 cup or 175 cc) and filtered it back into the pump through a coffee filter.

There was no crud or visible debris on the filter although it did turn dark from the fluid. New PS fluid is clear; I suspect that this stuff is original and simply "old" and discolored with age and heat.

There is nothing in the factory books about changing the fluid and no service records mention it even though the car has 248000 four-owner miles.

I plan to do a complete flush of the power steering system and then see what happens. It would be nice not to have to replace the pump if it isn't necessary. I also hope that it isn't the rack.

Jeremy

KermitF · #12 11-15-2007, 10:37 PM

Jeremy,

The instructions Larry gave you are basically all there is to it.

With 248K mi. and no records to show this has been done previously - do it.

(You can do a search on this forum and it will provide additional (and good)detail on the job, but it is easy to flush this way and results are noticeable.)