Well, mine officially failed on Sunday, and took out the serpentine belt with it (at least I managed to make it home).

Options, replace pump myself and belt at a cost of around $400 to $500..
Or Tow and pay MB around $1600.. Which I really would prefer to avoid.

I know, I started a thread about this earlier, but that had a slightly different topic, there is no rebuilding it anymore.

The official instructions state to loosen the engine mounts and lift the engine slightly, which I do not have the ability to do... Hoping it can be done without moving the engine around.

 

Hi jvanbrecht,

You could rent an engine cherry picker to lift the engine a bit so you could access the unit properly. However, if you don't have the proper tools (or skills) it may be better to bite the bullet and let the dealer or a good Indy shop do the work. I've done a lot of work on various cars I've owned, built engines, suspensions, etc. and having the correct tools to do the job is essential. I learned that in some instances it's better to just farm it out to a local expert. Also remember, the C63 is not cheap and sometimes you have to pay to play. Best of luck in resolving this issue.

 

So what did you decide to do?? I'm in the same boat. My pump is whining badly. Steering feels fine, fluid is good, it just whines like crazy. Sometimes even at idle. Starting to feel some jitters with slow steering too, gets worse each day now that I've noticed it. Would love to DIY it if possible.

 

I'm not the OP but thought I would answer this as I was not able to find anything when I needed to replace mine. Yes it is possible to do this without lifting the engine. I did it myself.

First you remove the serpentine belt. Then there's two bolts holding the power steering pump bracket to the engine that you access on the front side. You can reach down and get to them with a regular ratchet and torx socket.

Then I removed the front undertray to get access to the backside of the pump, where there are two more bolts. You have to reach up and it's a tight fit because youve got the frame right in the middle of where you are trying to reach. One of the bolts is decently easy to get to with a socket extension. The other bolt closer to the engine was a real pain to get to. I ended up using multiple extensions and swivels to get to it.

After you you remove all 4 bolts, you need to remove the feed and return lines from the pump. The return line is held on by a hose clamp, and the feed line is held on with a large hex head banjo bolt. I removed these lines last because I didn't want fluid leaking down on me when I was under the car. Also, the frame was in the way of trying to remove the banjo bolt, so once the pump was free, I was able to rotate the pump to get better access to the banjo bolt.


Once those two lines are removed, you can just barely get the pump out upwards past the upper radiator hose. Installation of the new pump is just the reverse of this. Make sure to bleed the air out of the system and top up the PS fluid to the proper level!

 

How did you bleed air out? It doesn't actually tell you how in the WIS since they use a positive pressure pump to fill the system.

 

The way I did it was:

First I jacked the front wheels off the ground. Filled the reservoir to the cold max level. With the cap off, and the car off, I moved the steering wheel lock to lock about 15 times. Refilled to max cold level, and put the cap back on. Then I started the car and moved the wheel lock to lock a few times. Turned the car off and repeated the previous steps 2 more times.

 

The pump can be whiny because the filter is clogged.
With the old cars, the filter was visible. You clean it up and replace the fluid and the whining gradually goes away.
With this car, the filter is hidden and non removable. Also it's not included in the maintenance schedule and not shown in the factory shop manual.
Basically you have to replace the plastic reservoir at the top. If you cut the reservoir afterwards, you will see the filter glued inside in a diagonal position.
A new reservoir is less than $50 from the parts suppliers.
I did a partial fluid replacement on my car which reduced the whining a lot but am looking to replace the reservoir soon.
Mine was not whining bad but I was starting to hear a bit when cold.

Oh and to bleed the air you have to lift the front of the car so that the wheels are off the ground and then turn the wheels all the way in either direction a number of times while watching for foam coming out, the engine has to be off. Look it up on YouTube, you need a plastic bottle too.

 

I pretty much did the same thing. Not a full flush, but renewing 50% or more of the fluid made the wine go away.

It's a self bleeding system, (why the dealer forces fluid through) but having too much air in the system when you first start the car is not great for the pump.

I asked because there's several ways to bleed a PS system. When I did the vehicle off method turning the wheel lock to lock to force it through the rack it didn't do a very good job.

 

Thought I'd chime in here. I have an 09 C63 with about 85k miles. My power steering started shuddering and making whining noises like it was low on fluid. Checked fluid level and it was fine. After seeing the post about the filter in the reservoir I figured I would start there. I replaced the reservoir with a genuine MB part, sucked out as much old fluid from those hoses that I could, and topped it off with Pentosin ch11 or 11ch fluid. It's back to normal now, and it cost about $75 for the part and fluid.

 

Did you have to go through the bleed method as above when you replaced the reservoir? Or did you just replace it, fill and go?

 

just replaced it, put a suction line down the feed to the pump to suck out as much as I could, then filled it up. When I started the engine, I turned the wheels back and forth a few times slowly under its own weight.

Next day i drove to work and just added a tiny bit to level so it was full on dipstick. That was it.

 

Awesome thanks. I might as well do the same as my fluid was black when I flushed it last week.

 

VERY good info on this topic... I feel like it should be stickied lol. I might try this in the coming weeks. I've been experiencing some light steering shudder when I turn at a complete stop. The reservoir seems like the most logical and inexpensive place to start. I checked the fluid this morning and it's a little low. Color looked relatively clean and not black when I wiped it on the napkin, but I'll only take that at face value because it was the fluid at the top of the reservoir... Who knows what the rest of the fluid looks like. However, I did notice that the inside cap had white bubbles on the rubber part. Air in the system? Moisture?

Edit:

BLKROKT when you flushed your system, what method did you use to flush the system? I've done a power steering flush on a some Nissans back in the day... All I did was suck the fluid out with a baster lol and remove one of the lines by the rack itself. Would it be safe to assume this method is relatively the same or is there something I should watch for?

 

My filter, with the new reservoir/filter, the steering is quiet.

 

Filter looks fine so it probably wasn't worth the effort.

Thanks for taking one for the team though

 

Well, truth be told, I already had done a flush with new power steering fluid couple months before and wanted to see if I can make the Power steering system even quieter.
However, you meant to say that the filter is transparent.
But here is the difference between transparent grey and just wiping it white.


So I think it is worth doing both things at the same time, reservoir for around $30 and OEM fluid for around $36 a bottle.
However, if you just want to do the flush, you would be in good shape.
And yes, there was no way to know for sure without cutting it open and I wanted to know for sure.
You're welcome.

 

Wasn't it a huge PITA to swap out the reservoir?

For sure it's dirty but a full flush is all you really need, no?

 

Why huge PITA?
1. Cut whatever plastic bottle into a tray, I had a jug from apple juice.
2. Take off the silver engine cover over power steering reservoir.
3. remove the y shape air injection hose, doesn't even have clamps.
4. The reservoir is held down by 1 easily accessible screw, take it off.
5. There is a thin hose that goes to the left air injection capsule remove it and unclip it from the reservoir.
6. there are some hoses that are clipped down, the two power steering hoses, unclip them from the car and the left side coolant hose, unclip it from the reservoir.
7. Now lift the reservoir up and put the tray under it
8. remove the bottom big hose clamp, push it out, let the reservoir empty into the tray.
8. The top hose has a non removable clamp, replace it with a standard screw style hose clamp., also the factory big hose clamp is that spring style, replace it with a screw style, for more positive clamping.
9. Remove from the left side of the existing reservoir, the clamp that holds the coolant hose, to re-use it on the new reservoir.
10. put the hoses back in, tighten the clamps partially, position the reservoir in place, final tighter the clamps, clip all hoses back in, put the screw back in, put the y hose back in.


11. Using the front middle jacking point, jack the front of the car till front wheels don't touch the ground anymore.


12, Pour new power steering fluid in till the reservoir is full.


13. get in the car, don't turn the engine on, put the key to on without cranking.


14. Do 30 turns of steering wheel lock to lock, meaning go 30 times to full right 30 times to full left.


15. check level and add fluid.


16. Start car, let it idle one minute, turn it off add fluid.


17. Drop the car down, start the engine, do 10 turns lock to lock, add fluid.


18. Drive the car around the block check add fluid, put the silver piece back in place,


....Lots of typing, but very little work to do...


When you flush, you do 90% of the above anyway..

 

Flushing you just redirect the top hose. Isn't it a compression clamp?

I dunno, 5s of hose redirection vs 10+ more steps = PITA to me. Maybe I'm just lazy lol...

 

While you only redirect the top hose, you have to find a way to catch the oil that will rush out of the reservoir and out of the hose.
I like my work neat, so for me, this involved (3 months ago when I was flushing) lifting the reservoir and putting a tray underneath.
I'm not saying you can't just yank the hose, stop the oil with your finger and put some kind of cap on both the hose and the reservoir, but it is a bit tight in there to stick your fingers and do all this with reservoir still in place.


I also understand that by not disconnecting the supply hose you probably won't have air in the system and may not need to go through the air bleeding procedure.


I did confuse the hoses and disconnected the supply hose briefly so some air came out during the bleeding.


But even if this confusion did not happen, I would have done the bleeding procedure anyway. I err on the side of spending more time, to make sure the work is complete and proper.


The big hose, which is the supply hose, has one crimped clamp and one elastic/compression clamp.
To me, this elastic clamp became soft in the years that it was around. There was oil sweat around it.
Obviously, since there was oil sweat, there was air coming in and therefore this could be the real and simple reason for which so many of these engines have a hum/buzz from power steering.
(engineering wise, I believe that all engines of the same model have the same problems, so maybe all M156 were affected by an accountant somewhere in an office at Affalterbach choosing to click on the purchase of cheaper compression clamps, in order to save $20,000 per trimester and get a bonus at the end of the year; the cheaper soft steel clamps cause the older engines to mooh, buzz and hum, but that is neither-here-nor-there)


I ended up replacing this with a screw clamp, but there was enough room on the reservoir nipple to keep the compression clamp too.


The top hose, where the flushing should be done, has two crimped clamps, so you have to cut one and replace it with a screw clamp.

 

It's crazy that fluid replacement is not part of the maintenance schedule.

This is the colour of my fluid now, and that's after I did the lazy flush by replacing the fluid in the reservoir a few times. It looked like old motor oil before that.