Power steering suddenly heavy at times..
BTW, while we are on the topic of fluids: what would happen to the engine if someone poured mineral oil in there instead of say Mobil1 0w40?
My friend succumbed to that as part of "diagnosis" by a questionable mechanic lol
Told him to flush it out of there asap...
Last edited by VVF; Sep 6, 2013 at 01:02 AM.



BTW, while we are on the topic of fluids: what would happen to the engine if someone poured mineral oil in there instead of say Mobil1 0w40?
My friend succumbed to that as part of "diagnosis" by a questionable mechanic lol
Told him to flush it out of there asap...Mineral oil, like Marvel Mystery Oil, is usually a mixture of chlorinated solvents and pale mineral oil. They are really not suitable for use in a Benz. The mineral oil is OK for removing lead oxide, but who uses leaded gas anymore? If you have a piston aircraft, it is useful in those engines because aviation still uses low lead avgas. The mineral oil mixtures also form HCL which lowers the TBN of the oil, thus not indicated for Benz engines or any car that has an extended drain interval.
I don't think he has spoiled his engine with temporary use, but if one had used Mobil 1 0W-40 all along, he would likely have none of the maladies' suffered with conventional lubrication.
I would suggest using Liqui Moly Engine Flush (about $10 in USA) to remove it as soon as he can. The Engine flush is added to a fully warmed engine, then allowed to run at idle (only) for 10 minutes. Then evacuate the oil following the normal oil change process. I have used it on Porsche engines that I tore down. They were cleaner than other products I tried that were mostly kerosene. The "Baby-Batter" that forms on the valve train was mostly gone.
We don't know the history of car's maintenance anyway...Thanks for the useful info re: the oil and liqui moly flush
Btw, who's the manufactor for mercedes PS pumps?
Found a cheap new ZF pump here: http://www.ebay.com/itm/POWER-STEERING-PUMP-MERCEDES-BENZ-C-CLASS-W203-S203-CL203-C-180-C-200-/370892899663?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item565af0854f&vxp=mtr
Don't know if it's a fake/bad copy though.. Guess it's an aftermarket one. It was very cheap compared to the prices here in Norway atleast. But maybe it's not smart to put it on my car..
Last edited by Steff95; Sep 7, 2013 at 02:27 PM.
Just hoping my rack isn't damaged already.
Last edited by Steff95; Sep 13, 2013 at 12:43 AM.
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It seems like the pump from eBay is exactly the same as I got from a firm selling mb parts.. And I paid a bit more than from ebay, hehe.. But at least I received it fast, and now I know it's a "safe" pump
I know how to bleed the system though, manual to manual lock with car turned completely off, but what's the easiest way of flushing, and how much fluid do I have to fill each time before draining again? Is it necessary to fill up the reservoir full each time? Will I damage the pump if not?
Last edited by VVF; Sep 15, 2013 at 05:43 PM.
I'll just have to try flush it and cross my fingers.. Is there really anything else I can do, or should I just try? Maybe the damage is done already, I guess I don't have anything to lose..
Can anyone explain to me what these small metal parts do to the rack? I mean, does really even the smallest metal part kill the rack? How? I know it would wear/tear the rack more of course, but is there anything like gaskets that gets worn out before anything else? Or is the whole rack garbage after something like that?
And what's the return and out line on the pump? Is the steel pipe the out line, and return coming from the cooling system?
Last edited by Steff95; Sep 16, 2013 at 05:01 PM.
I recieved one litre of oil a few days ago, and did a flush... I spent around 0.7L to flush away most of the metal particles.. I actually ordered 2 litres, but they were out of stock... So I think I'm getting the 2nd one tomorrow....
My problem though, is that I only flushed the steering rack, not the cooling system/return line. So I wondered if it's possible to use another kind of oil (that doesn't have the 345.0 approval) for flushing away all the bad metal particles ONLY in the cooling system, and then use like 0.2-0.3L 345.0 approved oil to flush away the "bad/wrong" oil? I will disconnect this from the steering rack and PS pump of course. Because these parts should already be clean/empty for metal particles.
(There is already around 0.3L new 345.0 oil in my steering pump/rack system, so I have some spare for flushing when I recieve the other can of oil... But I don't think I have enough to flush away all the metal particles from the cooling system, that's why I wondered if I could use another kind of oil to remove these particles from the cooling system/return line, and then flush the bad oil away after?
I hope you guys understand what I mean, and it wasn't quite as easy as I would think to find this oil... I didn't get the pentosin chf 11s, but a similar one (febi 21647 I believe). It has the mb 345.0 approval, and it has the correct colour (green/"amber green).
Last edited by Steff95; Sep 25, 2013 at 03:43 PM.
I believe it should be able to capture the majority of the particles...
Depending on how you flushed it, you may have "automagically" flushed the return line.
Basically the operation is like this: pressurized fluid from the pump enters the left/right portion of the rack, depending on how you turn the wheel. Conversely, the un-pressurized fluid from the opposite portion of the rack is forced out via the return line back into the reservoir.
See this picture. I think the cooling line is a part of the return line, but it doesn't really matter.
I believe it should be able to capture the majority of the particles...
Depending on how you flushed it, you may have "automagically" flushed the return line.
Basically the operation is like this: pressurized fluid from the pump enters the left/right portion of the rack, depending on how you turn the wheel. Conversely, the un-pressurized fluid from the opposite portion of the rack is forced out via the return line back into the reservoir.
See this picture. I think the cooling line is a part of the return line, but it doesn't really matter.

What I did, was that I unplugged the steering rack hose from the cooling system under the car. Under the front bumper passenger side. From what I understand, there goes a hose/pipe down to the steering rack, followed by a hose from the steering rack over to the cooling system where the oil is being cooled down, and reused.(?).
So what I did, was to disconnect this hose, and turn the steering wheel lock to lock a lot of times, until I saw new oil coming out, and trying to remove most of the metal particles.
That's how I did it, so I guess there's still some metal particles in the cooling system part. Please let me know if you didn't understand.
Another thing is you flushed the system without pressure, so there could be metal particles still left in the rack. I would install an inline filter and turn the wheels many times lock-to-lock with the engine running and PS full. Then replace/discard the filter and all should be fine.
Last edited by VVF; Sep 25, 2013 at 10:18 PM.
Another thing is you flushed the system without pressure, so there could be metal particles still left in the rack. I would install an inline filter and turn the wheels many times lock-to-lock with the engine running and PS full. Then replace/discard the filter and all should be fine.
Okay, I could try that. Just hope I can find a good filter somewhere then...
Last edited by Steff95; Sep 26, 2013 at 01:17 AM.
Another thing is you flushed the system without pressure, so there could be metal particles still left in the rack. I would install an inline filter and turn the wheels many times lock-to-lock with the engine running and PS full. Then replace/discard the filter and all should be fine.
I was thinking of placing it right before the PS pump on the return hose.(After the cooling system/pipes in front by the radiator), so the metal particles won't get into the new ps pump... But I guess it's not good if the oil flows too slow through the filter, and the pump runs with less oil when having full wheel lock.(?)
Is there any difference between the filters, or can I just use a regular petrol/fuel filter for example? As long as it stops the small metal particles..?
There are filters for PS systems, and other cars are using them.
You will only have it there for a small amount of time, to get the last bits of crap from the fluid. You could also try a magnet, but I'm not sure if the shavings are magnetic or not...



Do not fear the hose clamp on the return hose. It is a CLIC or CLIC R type. It has an advantage over the "aircraft" screw clamps. The OEM clamp is easy to remove and replace with an under $20 tool.
These clamps are better because they have a little give in them and will not cut into the hose or break the nipple from vibration.
I don't think running the pump helps flush the fluid. Gravity and turning steering wheel from lock to lock will move the fresh green stuff through the rack without any strain on the pump. Disconnect the return hose at the pump and blow compressed air through the hose. The use of solvents in the hoses, pump, or rack might damage the components, and won't really remove any more of the spent fluid than new fluid.
You can buy the CLIC tool on Ebay.
Do not fear the hose clamp on the return hose. It is a CLIC or CLIC R type. It has an advantage over the "aircraft" screw clamps. The OEM clamp is easy to remove and replace with an under $20 tool.
These clamps are better because they have a little give in them and will not cut into the hose or break the nipple from vibration.
I don't think running the pump helps flush the fluid. Gravity and turning steering wheel from lock to lock will move the fresh green stuff through the rack without any strain on the pump. Disconnect the return hose at the pump and blow compressed air through the hose. The use of solvents in the hoses, pump, or rack might damage the components, and won't really remove any more of the spent fluid than new fluid.
You can buy the CLIC tool on Ebay.
And the clamp on my car was a normal screw clamp which I untightened with a screwdriver.
What do you mean by using solvents? Never heard that word before.
Last edited by Steff95; Sep 27, 2013 at 12:30 AM.



