C320 2002 Power Steering Flush DIY
How much PS fluid does the car hold? I know I won't get all of the old fluid out, but I think doing it maybe once or twice in the coming days should net a nice amount of it.
How much PS fluid does the car hold? I know I won't get all of the old fluid out, but I think doing it maybe once or twice in the coming days should net a nice amount of it.
From what I can tell the reservoir holds around 30-40% of a quart, and overall the system holds maybe 3/4 of a quart.
Comparing the two methods:
* Hose drain-and-fill ... one shot, you get > 90% of the fluid, including a lot of what's in the rack chambers.
* Reservoir drain-and-fill ... you get 50% fluid change, leaving 50% old fluid. Repeat a second time and reduce your old fluid percentage to half again, so now 25% old fluid remains. Do it again, you're down to 12.5%. A fourth time, 6.25%.
So, in my calculations it will take four reservoir drain-and-fills to provide the same fluid change percentage as a single hose drain-and-fill. This also means you'll need 2 qts vs 1 qt of new fluid.
If you are okay with the cost of 2 qts of fluid and a piece of flexible tubing (I would recommend siphoning out with tubing vs turkey baster ... will be easier and you will probably get more fluid out), then this is a perfectly good option for you.
From what I can tell the reservoir holds around 30-40% of a quart, and overall the system holds maybe 3/4 of a quart.
Comparing the two methods:
* Hose drain-and-fill ... one shot, you get > 90% of the fluid, including a lot of what's in the rack chambers.
* Reservoir drain-and-fill ... you get 50% fluid change, leaving 50% old fluid. Repeat a second time and reduce your old fluid percentage to half again, so now 25% old fluid remains. Do it again, you're down to 12.5%. A fourth time, 6.25%.
So, in my calculations it will take four reservoir drain-and-fills to provide the same fluid change percentage as a single hose drain-and-fill. This also means you'll need 2 qts vs 1 qt of new fluid.
If you are okay with the cost of 2 qts of fluid and a piece of flexible tubing (I would recommend siphoning out with tubing vs turkey baster ... will be easier and you will probably get more fluid out), then this is a perfectly good option for you.

It took about 30-45 mins to do the whole job. The old fluid was a dark red/pink color, almost almond color. The new fluid looks like blue powerade. I use a large turkey baster that took out about 1.5oz per squeeze. I took out as much as I could with the baster, then refilled with new fluid (got it from MB themselves).
I then drove around the block, turned the wheel lock to lock a few times, and repeated the process. By the 2nd time, fluid was a lighter shade of red.
Another few turns of the wheel and another squeeze of fluid and the color was now more closely resembling the blue that came in the can. By the 4th time I squeeze out fluid, it was much cleaner, but still not 100% blue.
I will revisit it in a few days with another bottle of fluid to finish it off. I have yet to give it a full drive, but hopefully things are smoother.
And here is the old fluid:
1. Is there a way to flush out the old power steering fluid while I crank the car without actually starting it? I remember when I did this job to my old jeep I disconnected the power cable going to the distributer. The jeep just cranked with out starting and was able to flush it out.
2. How much fluid do I need? 1 liter or 2?
thanks!

The system seems to hold less than a quart. So if you do a drain from the bottom hose and only one refill, just one quart. However if you do repeated reservoir drain-and-fills then you might want to get a second quart.




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The system seems to hold less than a quart. So if you do a drain from the bottom hose and only one refill, just one quart. However if you do repeated reservoir drain-and-fills then you might want to get a second quart.
Okay, so I am very keen to do this as my fluid is now a browny looking muck. Have done a heap of research over the forums - thank you very much for all the info on here.
My thoughts are that the best option, also the most difficult/time consuming is as below but would really appreciate any concerns/thoughts/improvements any one may have.
Pros: Should remove all fluid in the system entirely and ensure no air enters the system - hopefully not damage anything!
Cons: a mission to do.
Basically, remove air intake and silencer. Release tension on belt and remove belt. Remove as much fluid as possible from PS reservoir. Fill reservoir with new fluid. Remove return line for power steering fluid. Extend line into basin. Ensure that you have reservoir kept permanently full as a assistant manually turns pump in correct direction (not sure yet - will check) until all fluid coming out of return is clean. Replace return pipe on reservoir - top off fluid if necessary. Turn wheels lock to lock 5 to 30 times to bleed any air that may have entered the system. Top up again if necessary.
Anyways, this is not a big deal for me as I have to replace Alternator bearing in the next week or so anyway so belt etc will be off...
Any thoughts/concerns would be appreciated!!
One suggestion -- on your last pump-through, let the reservoir drain past the inlet pipe of the return hose so you don't end up with a gusher of fluid coming out of the reservoir when you put the return hose back on. Then refill the reservoir and do your cycling to remove air bubbles.
Thanks for the reply. Great, good idea re letting the fluid drop below return pipe inlet before tyring to refit! Thanks
Okay, will give this method a try in the next month and post some pics/more details once its done.



)I was sure that Glyn had said somewhere that it was acceptable to suck out the fluid in the reservoir and replace it, and that's what I did when I replaced mine - but I can't find that post. I think if you do that, you probably should make your flushes more frequent (which, unfortunately, I have not).
That "factory" clamp on the left side of the hose is a Clic-R clamp. You can buy Clic-R pliers on eBay for under $15, and might be able to find them in the auto stores as well. Even though I ripped my clamps off and replaced with regular screw-on clamps before I realized what these were, evidently they are very easy to unclamp and reclamp.
Otherwise, if you are concerned about not picking the right hose to unclamp, you're going to get 90% of the benefit from just doing several drain-and-fills from the reservoir. I suggest you buy two quarts of replacement fluid for this.
Either way, the sooner you replace the fluid with fresh stuff the less long-term damage you will cause to your steering system.
-- John


This is the hose clamp that goes to my steering rack from the power steering fluid reservoir
Close up of the hose clamp that goes to my steering rack from the power steering fluid reservoir
I've marked up your photo with a green circle to indicate where I think you should be looking to detach the hose -- on the front side of the return hose.
In any case, repeated drain-and-fill of the reservoir is a perfectly acceptable way to replace the fluid, although it uses much more fluid because you're playing a half'ing game mixing new fluid with old each time. For this method I suggest running through at least two quarts of new fluid and plan to do at least 4 drain-and-fills in order to get 90% new fluid into the system.
Things Needed
Flat Head
Funnel $ 1.50
Fluid extractor
Bowl to catch fluid
P/S Fluid (Pentosin), 1 QT AIC CHF11S Price 20.99$
And 30 mins of your time
8MM Wrench
My Mercedes Book


http://www.napaonline.com/Search/Res...word&Nty=1&N=0
1. Remove Splash shield on the lower side of the car.. 6 Screws

Put it to the side..
2. Open hood remove plastic from the right hand side attached to air filter box

3. Open Power steering Tank cap and start sucking out fluid

Here is the color of my fluid that was in my car


4. After Sucking out the fluid from the tank. Time to go under the car and disconnect the cable coming from the Power steering rack. Like this

Place cable in a bowl

Let the fluid drain Keep cable inside the bowl now head to the top of the car
5. disconnect this cable

After disconnecting this cable i hooked another cable the same size to it.. And blew out the rest of the nasty power steering fluid.
^ ( You don't have to do number 5 but just to make sure everything is out )
6. ( Make sure you now plug back in cable number 5 ) Now Start Flushing out the old fluid by Pouring new fluid inside the tank.


7. Look through the motor area and look at the cable below that you disconnected before.. You will see old fluid starting to come out.. Keep pouring until you see new fluid ( Green ) pouring out.. THEN STOP
Should look like this

Nice and clean
8. Reconnect the cable under the car after all the nasty fluid is out..
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.
10. ( I had to do step 9 ) 5 times until my tank had no more air in the system or lines. I did have to suck a little fluid out because i had to much in.
Car steering is so much smoother..
The color of my old fluid VS my new fluid is just amazing..
Amber gold To Fresh Green
This is posted to help peeps





