Oxygen

A few months back a member from this board came to our shop ( TTMotorsports / https://mbworld.org/forums/members/9...torsports.html ) with a 2003 CL600 that had a serious problem with the front end sinking after being turned off for a few minutes.

The car also make a crazy crunching/cracking/dinging sound coming from the ABC pump and would not rodeo for more than a few minutes because the pump would not produce enough pressure.

Our first attempt to remedy the problem was to filter the ABC fluid but that had no effect and the car would sink to the ground after being off for about 3 minutes.

The front axle valve block was obviously malfunctioning and needs to be replaced along with the pump and the leaky high pressure expansion hose.










One of the first things you must do is suction off the hydraulic fluid in the ABC and PS tanks...




The front axle ABC valve clock hiding behind a maze of hydraulic hoses...



Front driver's side wheel well needs to be removed to provide access to the front axle valve block and the pressure accumulator...



The black bulb is the front axle pressure accumulator and it is on the same plate as the front axel valve block. The whole assembly is removed once the hydraulic hoses are disconnected from the valve block...



Here is what 7 years of improvement look like... the valve blocks are not manufactured by the same company...






Here is the new valve block assembled with the mounting plate and the pressure accumulator.

The valve block has 4 electrical connections and 5 hydraulic connections.. they are as follows:

SP: Pressure Accumulator
S: High Pressure Feed
T: Low Pressure Return
FB1: Front Left Strut
FB2 Front Right Strut







The new valve block installed and all hydraulic and electrical connections are assembled:



When I initially diagnosed the car I noticed that the high pressure expansion hose that connects to the pump was sweating a lot of hydraulic fluid on the surface and would eventually fail, causing the same failure that happened to my S600 months back. With the new pump working correctly I did not want to subject the old hose to the high pressure and it needed to be replaced.

Here's a comparison between the old and the new hoses...






Installation of the hose is a bit tricky.. the motor mount needs to be unbolted from the subframe and the motor needs to be raised a few inches since the hose runs underneath the crank pulley and the subframe...









Here is the new and the old pump. The older pumps were manufactured by LuK but they were since bought and are now manufactured by a company called Ixetic. Exterior case is exactly the same. The suction restrictor valve looks to be updated..




New pump installed and awaiting feed lines to be connected..

Oxygen

We also discovered that the IC pump has failed. The pump was replaced with a newer model...






The rear axle made clunking sounds when the car would be engaged in gear.. I discovered that there were 2 bolts missing on the rear axle connecting to the differential. The other 4 bolts were loose or half way out....



Cleaned the rear axle, replaced the washers and the 6 bolts.. torque to correct specs...

Oxygen

Of course after the car was assembled there are many more procedures before the car was "ready to drive"...

-Flush/Fill/Bleed Power Steering
-Flush/Fill/Bleed ABC
-Flush/Fill/Bleed Intercoolers
-Engine Oil Change
-New Belt
-Recharge A/C

Oxygen

We are located in Farmingdale, Long Island so if any of you guys are looking for expert ABC service/repair and don't want to pay out of your nose at the dealership, please call or come see us!

We are sponsors on MBW and have a ton of references for the work that we've done over the years.

Oxygen

Link to Ixetic (hydraulic pumps): http://www.ixetic.com
Link to RAPA (hydraulic solenoid valves): http://www.baika.de/portal/baika_pro...64,detail.html

bentleyboy

Looks good to me but it's a hell of a drive from London.

benz_addict

Man, YOU ARE THE MAN! And damn that car was messed up. Is it a members car? How do the bolts from the rear axle just come off?
*bookmarked*

SebaCL600

Yes, it's my car. I only have the car for a few months so I don't know how the bolts came loose. These guys are really great and provide service that no dealer will ever match. They checked out the car from front to back and fixed whatever needed to be done. They also kept me updated on the process of the repairs few times a day. So if anyone wants any work done to their car I highly recommend them. I know that I'm going back there in a few months for new lower/upper control arms, rotors, pads, lowering module and a tune. Thanks again Chris and Bruce.

JDB

Hi Oxygen,

I just want to compliment you on the highly documented repairs on that CL. It's truly rare that someone takes the care that you do, and also takes the time and extra effort to document things as you have done.

If I were located anywhere near your shop, I would certainly be dropping by to have you maintain my vehicles.

Great job!

JDB

V12Godspeed

As always Chris, you and Bruce are top Notch! Very well documented and nice work on fixing these issues.

BlownV8

Awesome work. The next thing that will fail is the upper idler pulley. Should have replaced that while you were in there.

~CL500~

First class post man. Very nicely done.

Busa196

+1 for sure

Mercedes22

Yes a long way from the UK. A great job, many thanks.

ivanj

Is an ABC fluid flush part of the recommended service? What is the interval? What should the dealer or independent charge?

When I purchased my new 2005 CL55 in 2006 it had been sitting so long I had the problem of a droppy suspension. The dealer ended up replacing the enite system except for the hoses. Alas, it took 4 trips to the dealership until they finally fixed the problem.

They told me that if the car sits for months the ABC filters, valves etc. get gummed up with bits from the manufacturing process.
MB has the free initial oil change in the engine so these bits are removed from the engine.
I think that MB should do the same to the ABC system so these bits are flushed from the system.

I almost insisted on returning the car under the NH lemon law but they finally made it right under waranty. The two AMG specialists at the dealer took it as personal insult that they couldn't fix the problem piecemeal as MBUSA wants them to under waranty so they really worked hard to fix the thing. Thank G*d I have another vehicle!

Oxygen

I don't know what the dealer's procedures are... I know the fluid and the filters are expensive so I doubt any of them would want to do this for free.

Maybe someone who works for MB can pitch in.

~CL500~

Regarding the axle bolts...

I just checked mine and all but two of them were loose! This seems like something we need to keep an eye on once in a while. Clunking noises when shifting may be indicative of the problem. Check your bolts!

benz_addict

Thanks for the heads up I will do this right now

blahuh

There is no recommend service interval for the ABC system. For the sagging suspension problem MB says flush, then if still present, replace corresponding valve block. I personally flush or filter the ABC fluid on any repair; strut, line, valve block, etc... I also recalibrate the level stored in the ABC control module after repairs to help keep down on comebacks. Don't know if MB approves but they havent denied any claims yet so Ill keep on doing what I am doing.

Exotic-metal55

Great info!! Will save people lots of money!!

sprins

Impressive description. Oxygen definitely knows his ABCs ;-)

ivanj

Thank you - will have them check this - it seems to be a common problem that some dealers are aware of.

Oxygen

I will be writing more articles like these as cars come in and out. I should be installing a new ABC tandem pump in a W220.176 S600 soon.

Interested in doing it on either a W221 or a W216, but most of those are still under factory warranty.

gordon harrison

Wow that is a serious documented repair, if anyone knows of anyone in the UK that carrys out their work to that standard please let me know as i have an ABC issue that needs looking at. Id agree with Bently, the US is a bit too far for the lads in Uk to go for a garage, pity these cars dont have wings as i know they fly!!!!!!!!!

Oxygen you are the MAN! Welcome to Machester any time.

bentleyboy

Hi Gordon,

Well I have to agree with all you said. I was the luckiest man in six counties because there happened to be a pump on ebay just at the right moment . From Chicago to Bristol, plus taxes, it cost me £350 'ish and £750 to have it fitted by main dealer ( that's Mercedes main dealer not Nelson Mandela).
Car was going fine until five weeks later the vacuum pum for central locking gave up the ghost...another £750......geeez, gimme a break will ya'
Still, car's going great again and turns heads still...best looker they made in past ten years.