Correct Power Steering Fluid for 06 E320 CDI
 

Ordered power steering fluid for my 06 E320 CDI....Pentosin CHF 11S according to manual and everything else I had read. Was a bit confused when I saw that the new fluid is green and the fluid I extracted is pale yellow. Two possibilities occurred to me: (1) the PO put in the wrong fluid (even though he was pretty meticulous and conscientious); (2) the same fluid can come in different colors.

Then I read a couple of threads from people with similar confusion, some even being told by MB dealers that the manual is wrong.

Dealer gave me wrong type of Power Steering fluid ....... or did he? - Mercedes-Benz Forum

Power steering fluid Colour - MBWorld.org Forums

http://mbworld.org/forums/e-class-w211/532806-mixing-two-types-steering-fluids.html

So, needless to say I'm a bit confused. I have a steering system filled with yellow stuff except a reservoir of green stuff...I have not started the engine yet.

Can anyone clear up my confusion?

I used Pentosin.Old fluid was greenish.I did complete flush and it is working nice.

On my 2006 CDI with 57,000 miles I used CHF 11S and it is light green. There is a 30 ounce capacity, I sucked out 6 to 7 ounces oz. 3 times and calculate I replaced 50% of the fluid.

It came out a very dark green and got noticeably lighter every time I replaced 7 ounces.

If you have a hose clamp and some hose, remove the return hose at the reservoir. Plug at the reservoir. Put catch container under open end of return hose. With the weight off with the front wheels, off the ground and without starting turn all the way to the right, top up level, turn all the way to the left watching and topping up, repeat till CHF 11S comes out and you will be fine.

For me I figure every other oil change I will freshen up the PS fluid by draining and replacing 7 ounces.

the CHF 11s is pretty good fluid but very expensive, its mostly for suspension systems. If the old fluid was yellow/bright amber then it was the dexron flavor PSF.

Except....I asked the PO and he confirmed he used CHF 11S, and he drained and filled quite a few times over the course of 100k miles. And over on another board someone confirmed that, in his experience, the Pentosin changes color after it's been in the system for a while (strange as that may sound). So I'm pretty confident that Pentosin is what has been used....but still mystified by the conflicting advice some folks have gotten from the dealer on the issue.

I think the only way to really compare these might involve finding it they have a ' military spec' number..
or using the MSDS information.

It is true that the chf11s does change from green to amber over time. It doesnt make a difference though.

If you want to test your fluid, suck out a small sample and get a sample of your fluid - put both into your freezer and check after 2 or 3 hours - the one that moves the same as you put in when warm is chf11s. Its got a ridiculous viscosity index.

btw - fluid that changes color are common, ATF+4 is one, transynd is another, toyota T-IV is one too. All change to an amber shade - the toyota one goes gray after the amber.