C320 2002 Power Steering Flush DIY
I have done this on my ML (same engine M112 as my 2004 C320).

P/S Fluid
Product Line: Altrom Chemicals, Lubes - Regular States
Part Number: AIC 0009898803
Price:
Availability: This part can only be purchased from your local NAPA Auto Parts store.
Warranty Warranty information is unavailable.
Material Safety Data Sheet MSDS Detail
Application Information: 2007 Mercedes-Benz C230
Per Car Qty: 1
Apparently, the approval number is 345.0.
There are equivalents from Fuchs and Febi.
The one in the blue bottle above is for another MB standard and doesn't seem to have the 345.0 approval.
RMEuropean shows these 3 being equivalent:
http://www.rmeuropean.com/search.asp...rd=Q-1-32-0001
Last edited by billbillw; Mar 5, 2011 at 01:28 AM.
The Best of Mercedes & AMG
I didn't notice any noise before or now, but my steering wheel does feel a little on the heavy side still. Should I do a full flush and do you think my pump is bad and how can you tell if its bad?
Happy Holidays!
Got Pentosin CHF 11S on Amazon for something like $20/L. The hose clamp was hard to find at first because it turns out they replaced the standard flat-head hose clamp with a friction one you have to pry open. Needle nose pliers did the job nicely and after that it was dead simple.
As for the symptoms, it drives like a brand new car. My fluid wasn't as orange as the fluid pictured here, but oh man, what a difference it makes. If you're having issues at all, definitely give this a try, it only takes like half an hour for a total novice, and helps a ton.
Question -- how much fluid did you need to refill the system? I want to make sure I don't use too much fluid for flushing out the old fluid and run out on the refill.
Thanks. John


I need to flush mine too... Bought the liquid a few months ago, but I am lazy, and don't have access to a lift. Maybe I will just ask at some mechanic place to use their lift or floor jack for 5 minutes to flush it and turn the steering wheel 30 times
Last edited by VVF; May 16, 2012 at 05:11 PM.
I didn't turn the wheel 30 times but instead did this: "9. ( Tricky Part ) Fill up the power steering tank.. Put cap on. Start the car for (three seconds ONLY) . Shut the car off.. Fill Tank back up. Do this 5 Times." I only did that 2 times and the fluid level stabilized.
Last edited by Ribo89; May 16, 2012 at 05:17 PM.
I did the reservoir-only method, draining and refilling 3 times (to use up the quart) and running the car around a bit in between each time. I got the fluid to change from a dark brown to light amber, but not quite green. I figure if the reservoir holds 1/2 the fluid in the system then I ended up with somewhere around 1/8 of the original fluid still in the system. The cold start shudder is virtually gone now. Not 100%, so I'm planning to purchase another quart and do this again sometime soon. After that, maybe once every two years when I do the brake fluid.
Also, fyi -- since the reservoir is about two feet above ground level, you can drain it using just a piece of hose as a siphon. Works really well -- just watch that you don't accidentally suck fluid into your mouth while you're priming the hose.
Last edited by jkowtko; May 16, 2012 at 07:00 PM.
I went to 4 different shops today and most of them are saying my Power Steering Pump needs to be replaced. Apparently... this is no easy fix.
Do you all believe this is really the problem? And could draining the fluid fix this noise? Thank you very much
Some suggestions on things to try before forking out $$$ for a new pump:
Check if the sound increases in pitch when you increase the engine RPM?
Try to pinpoint the sound by putting loads on the different components attached to the belt ... does the sound change when you:
- turn on Max A/C?
- turn the steering wheel
- turn on the headlights?
Try the "tuning fork" trick of touching a long screwdriver to the metal housing of each component attached to that serpentine belt, and listen and/or feel the other end of the screwdriver for where the vibration is strongest.
If you suspect the PS pump is the culprit and you haven't changed PS fluid in a long time (or ever) you could try drain and refill with the proper fluid to see if it relieves some of the load on the pump.
Some suggestions on things to try before forking out $$$ for a new pump:
Check if the sound increases in pitch when you increase the engine RPM?
Try to pinpoint the sound by putting loads on the different components attached to the belt ... does the sound change when you:
- turn on Max A/C?
- turn the steering wheel
- turn on the headlights?
Try the "tuning fork" trick of touching a long screwdriver to the metal housing of each component attached to that serpentine belt, and listen and/or feel the other end of the screwdriver for where the vibration is strongest.
If you suspect the PS pump is the culprit and you haven't changed PS fluid in a long time (or ever) you could try drain and refill with the proper fluid to see if it relieves some of the load on the pump.
here is a new video, in my attempt to showcase it a tad bit more. at first I was skeptical at the diagnosis, but after deciding to give it a listen after turning the wheel.... I think they are correct.
* Have you looked at the fluid level in the reservoir? When I replaced my fluid last time I had the level low and when I started the car the pump made huge amounts of noise ... its possible that a lot of what you are hearing is the pump mechanism grabbing at air.
* what's the color of the fluid? take a piece of clear plastic tubing or straw and suck out a bit of fluid so you can see the color. New fluid is light translucent green, like Midori ... old fluid turns amber and then dark brown. Any other color might be the wrong fluid type. If you think you have old or incorrect fluid I would suggest you spend the $20 on a quarter of CHF 11s and see if that helps.
* underneath it all it still sounds like there may be a worn bearing to me ... but I would try the simpler remedies first.
Last edited by jkowtko; Oct 31, 2012 at 07:50 PM.
* Have you looked at the fluid level in the reservoir? When I replaced my fluid last time I had the level low and when I started the car the pump made huge amounts of noise ... its possible that a lot of what you are hearing is the pump mechanism grabbing at air.
* what's the color of the fluid? take a piece of clear plastic tubing or straw and suck out a bit of fluid so you can see the color. New fluid is light translucent green, like Midori ... old fluid turns amber and then dark brown. Any other color might be the wrong fluid type. If you think you have old or incorrect fluid I would suggest you spend the $20 on a quarter of CHF 11s and see if that helps.
* underneath it all it still sounds like there may be a worn bearing to me ... but I would try the simpler remedies first.
)The bearing problem, what would that be related to? Or would that have to have a diagnostic performed? And once again, how bad will it hurt my pockets?
I had an appointment next week at the official Dealership but all the shops I went to basically told me to cancel it because they will steal my bank. I already went to them once, though, in which they replaced my Valve Gaskets (an $800 job, after the discounts I got for befriending a sales associate, lol)Thank you!







