ML 350 Power Steering Leak fix – With pictures…easy fix

Ok, so my Mercedes Benz ML 350 is just about to be 10 years old and to no surprise, on this model at least, it’s leaking power steering fluid.  I say no surprise because it’s had this problem since it was 2 or 3 years old.  I got it repaired twice for this while it was still covered by the dealer.  Since then, I’ve been just refilling it and sticking it out not getting it repaired.  The leak was small and it was not a bid deal.  NOT anymore!  It’s started to make a whinny sound and it’s leaking a lot more so I figured I would get it fixed.

I called the dealer and I’m looking at at least $250 to $300 to have the seal replaced.  Not bad I thought.


before I took it in I figured I would check to see what the parts ran.  I knew it wasnt much but I was really surprised to see that the parts needed to repair this leak was literally under $10 bucks and it’s actually closer to $5 bucks or less now that I think about it.  Here’s the breakdown.

O-ring (gasket): part#000-466-18-80 – $3.40 Look for it here or at Amazon.

Retaining Clip: part#000-994-19-03 – $2.50 Look for it here or at Amazon.

Power Steering fluid: The genuine stuff is CHF 11S

If you get just the o-ring, the clip was fine when I removed it and I really didnt see a reason to replace it but since I had already bought it, I replaced it with the new one.  You can really do this repair for just a few bucks and maybe an hour of time.

It took me an hour and that’s including having to stop, clean my hands and take the pictures.  It really is an easy repair.

Check it out below: All the images are clickable to see exploded views.

  1. Remove the engine cover, gently taking care to not break any of the plastic parts that attach it to the mounting sections on the engine.
  2. You’ll need a medium flat screwdriver – to remove the clip and the seal.
  3. Turkey Baster – to remove the fluid from the reservoir.
  4. Torx Tool – #10 to remove the one screw that holds the reservoir in place.
  5. New parts: gasket and clip and CHF11S power steering fluid (the good stuff)

1 new parts 1 torx tool2 1 torx toolchf11s

Remove the power steering fluid with the baster.  If the baster doesn’t reach the bottom of the reservoir tape a straw to the end of the baster to reach the bottom and suction out all the fluid you can.  The more you remove the less mess you’ll have when you slide out the reservoir.

2 removing fluid

3 baster


Now take the front screw off with the Torx tool.  It’s located in front of the reservoir facing the fan.  Should be easy to find.

4 removing one bolt


Once the screw is out slide a shop cloth or any piece of rag under the reservoir to help catch any excess fluid in the reservoir when you pull it out.  I used a piece of a blue rag.  You can see it under the reservoir below.

5 cloth under reservoir

Now remove the retaining clip on the back of the reservoir. Its under the hose on the image below.  The closeup below shows the area with the clip already removed.

6 clip view 7 clip off


I would say that the clip is fine and doesn’t need to be replaced but it’s such a small inexpensive piece why risk it.  You can see the new and old piece below.

8 clips


On the picture below you can see that the reservoir has been removed and the hole plugged.  That’s to make sure that no dirt or junk gets into the system.  The gasket will be on the inside of the reservoir where you see the napkin.  Pry it out with the screw driver, should be no trouble at all to slide it out.  NOTE she shape of the reservoir on the left side.  It’s notched.  You’ll have to make sure that the notch realigns with the bracket when you re-install it.

9 reservoir off


Here’s a shot of where the reservoir was removed from.  Clean up the reservoir and the inlet you see on the image below.  Again, being careful to not allow any dirt on junk into the system.

10a pump view


Once both the reservoir hole and the inlet are nice and clean slide the gasket onto the inlet.  Make sure the power steering reservoir gasket or o-ring is nice and snug all the way back on the inlet as you see below.

11 old and new gaskets

You can see how flat the old gasket is compared to the new one.

12 new gasket on


Now you should be ready to slide the reservoir back into the inlet.  When you do so make sure to align the reservoirs notches with the bracket and gently slide the reservoir all the way back till you hear or feel, in your hands, a light click.  The notch on the reservoir should be aligned with the notch on the inlet where you’ll place your new reservoir retaining clip.  Don’t forget to put your front screw back on and tighten it to spec.

13 reservoir back on


Two  more steps to go.  You’ll have to slide the new retaining clip into place.

14 new clip on


and refill the reservoir.  That should be it.  Make sure to refill the power steering reservoir with genuine power steering fluid ( I like to use the CHF stuff)  to the max mark on the dip stick and remember:


Which happens to be a pain in the a** to get out.

Again, easy breezy repair, which to my surprise is cheaper than buying genuine power steering fluid, the CHF 11S stuff which happens to be cheaper at Amazon than everywhere else I found it.  I’ve used the FEBI stuff before, the genuine CHF 11S works better.  The system doesn’t whine with the genuine stuff.  Just my observation.

All being said and done it’s a $6.37 (including tax) easy repair that takes less than an hour to complete.

Good Luck now all you have to do is clean up the driveway of all those power steering fluid stains.  Ha Ha Ha

Thanks for reading.


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