I have been gone for a while (thanks for noticing Howard ) and thought I would ruminate on my S600 project a bit while watching Sunday Night Football. As some of you may remember (and others may have no clue) I bought a 2003 S600 last December sight unseen from a guy in Texas. It is in good enough shape and for the most part mechanically sound but has a few issues that are, shall we say...pricey?

This may go on a bit long but I have the time tonight to sit with my laptop to review my progress. The major issue is the ABC pump. I took the car to two different independent Mercedes specialists for an estimate. I asked the first one to check on a few minor concerns but nothing that I thought was overly concerning. The biggest concern was to fix the ABC and the rest was just stuff that I knew I would have to tackle little by little over time.

Imagine my shock and awe when I got the call that the total for everything was $12,388! Of course my plan was to tackle it a bit at a time but...jeez! I asked them how much just to fix the whining ABC pump and was quoted $2700. I thought that was a bit much but the guy told me the part alone was $1700 and there was 20 hours of labor involved in removing and replacing it. I wanted a second opinion so I called another local independent MB specialist. The second guy quoted me $1500 so I picked up the car and drove it to the second guy.

When I got there he told me that his computer defaults to the S500 and when he rechecked it with the right car the S600 was going to be $2700.
I figured one guy was as good as the next and it was going to be $2700 at either place so I gave him the word to go ahead. He had it for a day and called me to tell me that the reason the pump went bad was because it was got low on fluid due to a leak at the "oil separator plate." This "plate" apparently was at a place that required removal of the engine. His REVISED estimate was $8000. He also told me that to get to the pump he would have to remove the coil pack and that it was likely going to destroy it requiring a new one at $2000 for parts and labor for at total of $10K.

At this point I told him to put it back together and I will pick it up. I have worked on cars before and USED to enjoy it but I haven't done any work on my own (except minor stuff like brakes) for over 15 years. I have never heard of this mysterious "oil separator plate" in all my years of working on cars. I figured I would just figure it out myself and replace the ABC pump on my own. I parked the car in the garage and put it on blocks and left it. I was working on finishing an advanced degree in nursing and had a lot on my plate. I also planned on taking a few trips over the summer so I left it alone in the garage while I got through my summer.

I have been online a few times over the summer researching how to get it done but I haven't had a lot of luck. I could not find any step-by-step instructions on r/r of the ABC pump. I did find a mechanic's site where a MB mechanic stated that to get to the pump you had to remove the front wheels, underbody covers, wheel well skirts, front bumper, radiator and fan, and driver's side turbo as well as the upper engine cover and air cleaners.

So this weekend I got around to tearing it apart and found that it wasn't all that after all. I took off the beauty cover on top, removed the air cleaners (didn't really NEED to remove the one on passenger side), took off the undercarriage covers, and got a good look at the part in question. Yes, it is tight. But with a little effort it was doable. I removed the dual reservoirs next to the pump that hold the PS fluid and the Pentosin for the ABC. After that I took off the radiator fan, the belt tensioner pulley, and the serpentine belt. After that it seemed a breeze (well, not a BREEZE-it is VERY tight in there). I removed all of the hoses and plugs from the unit and removed two bolts in front and one in the back and wiggled it out. It is presently sitting on my garage floor.

There are presently many threads discussing ABC pumps and members musing if they think it is something they can tackle on their own. It is tight and I had to get creative with tools on a couple of occasions (ie. putting a socket into a pair of vise grips to fit it into a tight spot) but I think this is something that someone with the proper tools can accomplish on their own. BTW, I DID NOT, repeat, DID NOT have to remove the coil pack. It is still sitting comfortably in place where it should be.

I have found remanufactured pumps for $800-$900 and new ones for $1100-$1200 online. I will be searching for the best deal this week and replace it when I get a chance. I am still pretty busy at work and with my business but a few hours work to save myself somewhere around $1500 seems worth it to me to bust my knuckles for a couple of weekends.

I have about 8-10 hours involved so far (HAD TO golf this weekend so I have been at it off and on and don't have the exact amount of time). It should be a bit less time to put it back together since I know how it comes apart but reassembly should present its own set of problems.

I don't know how the job books out at 20 hours labor since a garage monkey busting his knuckles over the weekend with crappy tools and absolutely NO KNOWLEDGE of the process should get it done in under 15 hours. Also don't know why they are removing the coil pack to get it out, ESPECIALLY since they are known to be problematic to remove safely and it is completely unnecessary.

I am perplexed by this "oil separator plate" they said I needed. If it does exist and if it is actually leaking then I will need to stay on top of the fluid levels to ensure I do not damage this pump by letting it run low. I have not been able to find any information regarding this mysterious part so I am just going to get the new pump in and keep an eye on the fluid levels and if it keeps leaking I will have to find the leak whatever it takes.

For now I will be happy just to get the car out of the garage. It's been there for 4 months and it kills me to see other S-classes driving around town. I need to get my baby back on the road.

Glad to be back after a long absence,

Keith

 

wow is all I can say, fair play to ya & keep us posted.

 

the mechanic was probably just trying to make more money off you

 

Keith,

Nice to see the progress you have. Seems you are still not too old to maneuver wrench.

One thing to mention, after the new pump is in, it will not suck the fluid at the very first time. To make it work the ABC reservior need to be pre-pressurized. Without this step the new pump will die very quick.

Here is what I did to pre-pressurize:
- You need to buy at least 5 liters of Pentosin CHF11S, actually I bought 20 L to flush the ABC and power steering. The ABC holds 4 liters and steering hold 1 liter;
- Get a hand pump with gauge at least 15 psi;
- Before start, make sure there is enough fluid in the ABC fluid reservior, I made the tank nearly full, as the pump and hoses are empty. Don't make it 100% full either as you need some air to hold the pressure.
- Attach a viynl hose on the pump, put the other side in the ABC fluild reservior through the small hole/cap which used to check fluild level, seal the hose firmly to the reservior;
- Pump to 15 psi. Make sure the system hold the pressure, check your connection if there is air leaking;
- Start engine and let it run like 20 second;
- Stop car and roughly check the fluid by taking off the filter cap when the pump is still attached. Fluid level getting low is good news which tell you the pump works and suck fluid well;
- Add more fluid in case needed then close the tank and pre-pressurized one more time;
- Start engine and let it run 1 minute, during this 1 minute, take off the viynl hose and use the cap/gauge to check the fluild level make level is ok, add more fluid when needed. Due to the R/R you must lost lots of fluid, so keep checking fluid level and be prepared keep adding fluid;
- Stop car and check for any leaking;
- Start engine again and let it run. This time you could use the ABC button try to raise/lower the car.
- If everything is fine you could start to check and adjust the fluild level.

Don't forget the power steering side although it doesn't need pre-pressurize. Make sure that reservior has enough fluid too.

Good luck.

Howard

 

THAT's why UDAMAN Howard. Thanks for the heads up. I knew that running the pump without fluid would be detrimental. I was thinking about the best way to prime it and your advice sounds good. Since you have tried and tested it I will give it a shot. I will be picking up some of the MB factory only parts this week so I am hopeful I will be driving this weekend. However, I am not getting my hopes up because I know how it is when working on cars. Never sticks to schedule....

Keith.

 

Yes, keep good work but don't rush. Any doubt, check or post here so we could help.

Howard

 

Keith,

I have to mention if I didn't. The reason I did the pre-pressurize is because my tandem pump sucked air when I was flushing the ABC system. At that time the pump no-longer took fluid and the pressure down to 0.
This incident was documented in my maintenance threads. And after CPR my ABC runs perfectly.

So mine is not exactly the same situation as yours. I believe the process I provided will work for you but I still want you think base on your specific scenario.

Howard

 

Thanks Howard. I will take your advice and heed your warnings.

 

So I managed to complete the process today. Got the rebuilt ABS pump in and reconnected everything. The car had sat for so long that the battery had gone dead because I forgot to put the trickle charger back on. I installed a new battery and got in to try to start the car. I was actually pretty shocked that the car fired right up immediately after sitting for more than 5 months. Got all kinds of warning lights on the MFD but everything cleared up as soon as everything got pressurized again. Gonna need more coolant, though. Anyone know if I can use Prestone or is the MB coolant a must? Anyone want to chime in here with coolant recs?

I had my son help me with trying to flush the system. I am not too sure if I handled this right or not. I disconnected the return line from the reservoir cap and attached that hose to another hose which drained the returning fluid into a oil changing pan. I removed the filler cap and made sure the reservoir was full and made ready with 8 more liters of Pentosin. (BTW...I believe I got raped by the local MB dealer for the Pentosin paying over $43 per liter. I will send them an email later to express my dissatisfaction at paying TWICE the going rate for the fluid.)

I then had my son start the engine. I did not hear the whine of a high pressure pump sucking air but there was nothing coming back through the return line and the fluid level in the reservoir was not going down. I let it go for about 10-15 seconds but I did not want to burn out the pump so I had my son shut it down.

At this point I took Howard's advice about pressurizing the reservoir with air so I put the cap back on and put about 10# of air pressure into the reservoir and had him start the car again (had to hold 2 holes on either side of dipstick cap to hold pressure). I was at least now getting some Pentosin back from the return line.

I was expecting dark, dirty fluid hitting the drain pan. However, the fluid coming back through the return line and draining into the pan was as green as the fresh stuff I had just put into the reservoir! Since I had the pump primed at this point I removed the filler cap and topped off the reservoir. We continued for 3 more liters of Pentosin and kept getting back pretty clean looking fluid so I shut it down topped off the power steering and the ABC reservoirs and cleaned everything up. I have to assume that the old fluid was fairly new cuz I could not get anything dirty to come back through the return line.

I took it off of the jack stands and buttoned everything down and took it for a spin. Everything sounded OK and it drove just fine at slow speeds going around the block (started getting a Pre-Safe warning in the MFD but nothing regarding the ABC). My son said I should take it up to speed on the main avenue so I went to the bottom of my street and got on the main drag and punched it.

At about 30 mph started getting a loud rhythmic scratching sound from under the car at about the area of the transmission! It scared the crap out of me so I pulled over and stopped. The noise stopped when I slowed it down so limped it back home nice and slow and no more noise. When I got back home I took a look underneath and realized that I did not replace the covers underneath the car and the one under the tranny was being held by the 2 screws in the back. At speed the cover was catching the wind and getting pushed down and scratching the ground. WHAT A RELIEF! Man, I thought I had messed up something bad.

Now I have some kind of coolant leak on the driver's side of the radiator. Gonna have to find the leak later this week and then I can put all the bottom covers back on and I am home free. Sounds great and runs smooth so I just have a bit more troubleshooting for the coolant and then she needs a SERIOUS detail.

Keith

 

My friend, I'm so happy for you. You rooooooock!!!

I suggest you stick with the MB coolant. MB coolant is good for 150k miles/15 years. Peace of mind worth the $20. Check the AutoPartsWay I gave to you earlier, good price too for coolant. I bought 2 and going to flush mine although I only have 75k miles.

For the ABC fluid, it won't be dirty as you assumed. ABC is not like engine, there is not much moving parts in it, plus it is working in a normal temperature. The only concern for me to flush the ABC regularly is the humidity. As most of the hydraulic system the fluid will suck moisture over time. Moistrue will rust parts in the system. For my case the valve start to show brown dots.

Anyway, I am exciting reading your story and you proved yourself a high level DIY MB mechanic.
Most important you enjoyed this super car in another way especially working with you son. This make me jealous. I want to teach my skill to my children but the two girls showed no interest,

Again, take you time to finish up, any question just let us know.

Howard

 

Hey Keith (and Howard),
Can I ask what kind of noise you were experiencing that indicated the ABC tandem pump was going bad? I've been chasing a whining noise over the last year and can't for the life of me figure it out.

It's a loud RPM sensitive whine that sounds like a wind up car or crank siren. At high 4000+ RPM, you might even call it a howling sound. I've got about 105,000 miles on the clock now. I've replaced all the idler pulleys and the tensioner pulley and belt but that didn't seem to affect anything (figured it probably couldn't hurt given the mileage).

For what it's worth, it exhibits no issues w/ the ABC system. Plugging into DAS and doing Rodeo, pressure is at acceptable levels. No leaks, and fluid was completely replaced about 10k miles ago when my high pressure hose burst (the noise ocurred before this incident).

As always, thanks for all you do to share information. It certainly has made my experience with this car more enjoyable.

 

Mark,

Sorry can't answer your question as I haven't experience noise from my pump yet.

Run it with belt off may help narrow down or use a mechanics stethoscope to nail the culprit.

Enjoy the weekend.

Howard

 

Mark,
Mine had a whining noise. It wasn't very loud but it was RPM sensitive. I agree with Howard, use a mechanics stethoscope to narrow it down. You can also check the damper for the ABC.

K