So, we had major work done on our ML350,
Mechanic is pretty good, new guy recommended to us by a friend. Formerly with dealer
Replaced the balance shaft and among other things, repaired the power steering and in general did a great job, running smooth. Not many people can do a balance shaft correctly. And he gives 24K mile warrany.

BUT.....except for one thing....
Shortly after repair, all the fluid in the PS was gone.
They needed to see it, so took it by and mechanic topped up with some crap from
Autozone in an autozone bottle and set an appt.. Mercedes calls for transmission fluid to be used, which I have, (Valvoline DexMerc) but
old mechanic and others swear we must use the expensive Pentosin stuff spec'd on every other
Mercedes but ML GL R. So we did. But i mean, only because it all leaked out.
3 or 4 times! My 2002 C has never had the PS pump replace or needed fluid. Ever! I
removed old fluid once with turkey baster and put in new fluid and that's all.

So fixed under warranty, but last time he saw the Pentosin can in the trunk and now says no more warranty on the
power steering, and fixed it 'one last time' because WE used the wrong fluid.
I pointed out we shouldn't have to be putting fluid in at all,we didn't cause the failure in the 1st place! And what fluid is he using ? Approved? NO!

So we discussed what is the proper fluid to use, and he gives me a quart of some **** from Autozone and says use this if it leaks again.
So a couple weeks go by, and we hear a noise from the front. i check the PS and damn, it waaaay overfilled! So much fluid it's pushing out of the cap and leakiing onto the pump! Damn! So I get a turkey baster and suck some out till it's at the correct level. But now worried we'll soon see another failure.
So wtf? This guy tells us he's not going to warranty anymore because WE are using the wrong fluid, when he is using some shiet from Autozone that is not approved by Mercedes? And we're using the wrong fluid ? And then it almost seems like he's sabotaging his latest work....what the F?
Not sure what to do.

Just hoping it doesn't fail again. He doesn't use Genuine mercedes parts either. Bosch steering pump. I Don't know how can feel he has a defensible position telling us he won't warranty because we use the wrong fluid when he doesn't use approved fluid in the 1st place. But getting into a pissing match will just result in us having to find a different mechanic, but I dunno...hard to find good people, unless you do it yourself!

What do you guys think?
If we have any more problems and he won't honor the warranty,, and we contact BAR or something, we'll likely lose him for any future repairs. As messed up as this one situation is, he did a great job on everything else. And much better than previous guy and of course dealer, fuggetaboutit! I wanted to contact him about the overfill but since I already corrected it, he'l probably think I'm full of it or something. But wow, what the heck?
Almost like he'd hoping to fry the whole thing with too much fluid and blame us, wreaking his vengence upon us.
Opinions please.

 

There is an o-ring between the p/s pump and reservoir. Mine hardened and started leaking so I replaced it (requires reservoir removal and reinstallation). Then I jacked the front of the vehicle as high as my jack would go and bled the system (slowly turn the steering wheel back and forth about 20 times to get any air out of the system) with the engine off. Could he have forgotten to install the o-ring or didn't bleed the system properly? I'm a novice Mercedes DIYer so I'm only guessing here. Any visible leaks other than the overflow out of the cap?

 

Please UPDATE YOUR PROFILE in USER CP to include the year of your ML.

 

Here are the only P/S fluids approved by M/B. The only Fuchs Pentosin PSF comes in a yellow can but it is only supplied in the Euro market.

You can check the rest on the list for availability in the U.S., but to simplify things, just get 2 qts. from the dealer.

And yes, the P/S system should have been bled prior to starting the eng. If the P/S is making a groaning noise, then the reservoir and O-ring must be replaced and the bleeding procedure followed.

 

Maj. Dundee..Updated my profile, but yes, it was posted in my sig.
Yeah, maybe he didn't bleed it?
What do guys think is up with this guy? Is he trying to sabotage his own work?
How can he complain about me not using the correct fluid and void any further warranty work, when
he using some scheisse from Autozone? I mean I didn't cause it to fail in the 1st place.
Fluid should have never leaked out. Any opinions of the subject?
He seems to say any old mineral based power steering fluid will do whereas the Pentosin is CHF 11s is synthetic. Just about any website you check says it's compatible.

 

Looks like the correct stuff is the Q1460001. Picking up 2 quarts and flushing the system!

 

My advise is to also replace the reservoir if it had not been done recently. I had a leaking steering system, fluid would leak from the reservoir cap, the pump was extremely noisy, and the steering felt heavy. I replaced the ~ $50 USD reservoir and everything is good as new. The issue was caused by the small filter/screen inside the reservoir, as it got clogged. A clogged screen will cause the pump to starve and cavitate ( which is very bad for pumps ), also, causing the fluid level to rise and leak.

Good luck.

 

i realize this thread is directing to the coupe model owners when talking about pentosin in a yellow bottle, but do all mercedes except diesel models use different types of pentosin, because mine is said to use CHF 11s in a green can?

 

I have already supplied you with the correct P/S fluids and Fuchs PENTOSIN PSF is one of them and it comes in a yellow can.

 

Where did it leak out? did you see any fluid on ur driveway or in engine bay?