loudandheard

You definitely scared me, but those were the symptoms gt4awd was having.

gt4awd

The other photographs only show the front side of the rotor... Glad it was just fluid! Let us know when you pull your current pump to swap with my old (now new) pump. Hardest and most time consuming part is getting at the rear bolts. This photograph should help you some.



Specifically the bottom left bolt. I had to find a small enough shorty ratchet to get in there with room to move. Ended up getting smallest one I could find at Sears.

loudandheard

This is probably going to be the most difficult part of the job and I'll see if I can document it as well. That way we can compare processes.

So how is your new pump doing? Every thing working ok so far? Any thing I have to watch out for, such as fluid level.

Did you suction out the fluid from the reservoir and then remove the pump, what did you use to get out the fluid when removing the pump? I just bought a mityvac and I hope that will do the job. I think I'll change the supercharger oil while I'm at it.

gt4awd

The new pump seems to be running without any issues. I do get a vibration in the steering wheel when turning while stationary, and of course that weird sound. Don't remember either being as present before installing the pump. Correctly bleeding the lines, and rack of air should keep the fluid level right where you put it. Noticeable bubbles will exit into the reservoir until all air is out.

Mityvac should work great to drain the reservoir. I just pulled mine off, and plugged it real quick to drain in a oil container. Didn't make too much of a mess. The pump will drain when you pull the pressure line to pump connection. I didn't do a full drain of the rack, but with the amount of PS fluid I've ran through the system I doubt there's much old fluid left.. I was at the dealership so often for PS the parts guy probably worried I was drinking the stuff. I think you would be able to do a full drain by turning the steering wheel just as you do for bleeding.

Did you get the OE Jet Oil II or the older type oil through Mercedes for the supercharger?

loudandheard

You may have some suspension components that need ot be replaced. I have a noticeable creak when I turn my wheel. I do not have a vibration in my steering wheel, so I think that may have to do with your suspension. I hate to say it, but maybe it's the steering rack.

I have the new type. I got a whole can and I'm sure I could send you some if you want some.

gt4awd

The steering system works just fine, and hopefully it will continue to do so. I've wasted too much money on that particular system of the car... If you could send me enough oil to refill the supercharger I would really appreciate it! When do you plan on swapping pumps?

loudandheard

This weekend.

loudandheard

So I finally finished doing the job today, but I still have not had a chance to drive the car yet. It's been freaking raining for two days, but luckily I had the car partially under a car port.

We need to make a thread about how to lift/raise the car because it was a pain in the *** trying to get it on jack stands.

Well, I almost had every thing done yesterday but I encountered a problem. Instead of removing the whole pump, as Iinitiallly was going to do, I was just going to remove the front half and install the rebuilt portion. The rear portion does not have any thing that needs to be replaced. Well, in another thread I read that the bolts had to be torqued to 35nm or 26lbs and I ended up breaking a bolt in the pump. I think my torque driver was either to large or the torque specs I used were incorrect. I managed to tighten the bolts to the point that they wouldn't be able to move any more.

So I figured I would just remove the pump and install the other one I had rebuilt. This was a hell of a job and I was unable to find a E12 1/4" socket, but we did figure out that a 10mm hand wrench will turn the E12 bolt.

The easiest way of doing this job is to remove only the front half off the power steering pump and installing it that way, do not bother to take off the whole pump, it's more difficult and absolutely unneccessary. I would recommend replacing the power steering pump resorvoir gasket.

I will post updates and pics, later on today. I will probably have a mini diy on how to take out a brocke bolt. Wish me luck.

gt4awd

Any progress? I was on vacation for two weeks. Just read this thread. That sucks about the broken bolt... Let us know what's going on.

loudandheard

For the past few weeks, it's been hectic. I've been working a lot and I have not had a chance to check every thing out, but so far the power steering pump seems to be holding up. I will be doing my oil change this weekend and I will see if in fact the leaking has stopped.

Hopefully I can get every cleaned up and the other pump put back together. Working 12+ hours a day sucks, but I'm sure I'll be able to do some work on it this weekend.

I'll make sure to take pics of the one I pulled out and do a comparison. I did see an odd groove in the one I took out of my car, that I did not see in your pump.

ML500K

Awesome DIY! I took my car for a check up cause I was losing PS fluid. I topped it off last week when I changed my oil. This morning when cold starting I can feel the PS fluid was low. Makes some noises when cold. Turned out the pump was leaking oil. The front gasket to be exact. I had my mechanic order the gasket parts listed. The gaskets and o-rings fit perfectly.

When they diagnosed the problem they said probably have to change the pump, I was like "wait let me check!" they were very surprised the gaskets fit... All I can say is Thank you loudandheard! Mbworld saved the day again. It was about a 2 hr job.

loudandheard

I'm glad that I was able to help out, gt4awd deserves thanks for making this all happen.

carbizindio

I finished my pump the other day and thought I would leave my 2 cents.


The best way to take the rear bolts off that I found was craftsman has this new type of ratcheting wrench that has more points than normal, its the only one painted black.


I used all but 3 gaskets from the set. Not sure if that was correct or not.

It took me 45min to get that small clip off with 2 picks, i think i ended up stretching the metal enough to work its way off.


On the 4 main bolts holding the pump together I measured the torque in reverse and it broke lose at 22nm or 16 ft lbs. I torque it back to the same spec's and have not seen any signs of leaks so far.


All data said this power steering system automatically bleeds its self.
WIS said you have to bleed it with the car turned off by jacking the vehicle up and moving the steering wheel all the way to one side back to the other until all air bubbles are gone. It mite take up to 30 side to side rotations until the air is out.

rmbaker47

I found loudandheard's great PS Pump rebuild post from a post on Mercedes-Benz Forum while looking for step-by-step instructions on repairing my leaking PS pump . I am new to this forum and need the PS pump removal and installation information that was mentioned as coming in the next post on the thread above? Loudandheard, please let me know if you have posted the removal/install steps or could share them at this time. Looks like to get at the PS pump I need to remove the radiator/condenser assembly - is that at least where to start?I

c32used

Sorry to bring this up it's 5 years old but how we know it's the pump and not the reservoir tank and o-ring that's leaking?

Khan 55

Well done for the effort and time and consideration of others to create a DIY post. Agents sold me a tiny o-ring which they call a seal and told me that's what should be leaking on mine. Will see one day when I have load of time to strip and dismantle the pump.

loudandheard

It's been a while since I've posted, but I figured I should let everyone know that you can do the full process without removing the full pump. You can remove the front 4 bolts and still do the rebuild. The rebuild is only on the front half. Istook the whole thing out because I was figuring out the process. Just make sure everything is clean and you are careful with the reinstall of the front half. It's a lot less work this way, but you have to be more careful.

Also the leak is from the front seal and not the revoir.

The write up is applicable to various models, but removal is different for each one.

precisionmike

I realize this is an old thread. I cannot determine if this was done on a c32 or c55. I have a c32 with the same issue, it is not the reservoir gasket. Has anyone else done this on a c32 with that part # for the gasket kit? Thanks, Mike

Brent Cook

@precisionmike This pump appears to be a 1124660101 according to the one picture of the side plate, which is the right one for a C32 M112K engine.