carlosinseattle

I'm so scared to post this question. I have a 01 S600 81K on the odometer.

I took my car to an independent shop because I had been getting a groaning noise from the front end of the car. Another independent shop had diagnosed it as a power steering pump. The dealer thought it was my AC condensor. I had problems with the first independent shop misdiagnosing things before, which is why I took it to the dealer.

I had the independent guy replace both the AC condensor and the power steering pump. The groaning noise was still there. He performed the rodeo bleeding procedure several times over a couple of days thinking it was just more air trapped in the system. He finally realized it was the front accumulator. He replaced it, and the car sounds great and drives great too.

I picked up the car and loved the sound and ride; it was just like old times.

Then I noticed that the car sat a lot lower the next morning. It had dropped around an inch an a half overnight, but that didn't bother me too much. The car raised to normal height as soon as I pushed one of the height buttons. The next morning the car was practically sitting on the tires. That really bothered me so I took the car back to the shop.

He bled/rodeo the car again a couple of times. He said that didn't help, so he checked everything else and said it has to be the valve block. Has anyone else had this problem before? And is there anything he could have done to cause the valve block to break? As you know, this has been expensive, and now it's getting ridiculoussly expensive.

Any help/suggestions are appreciated.

Oxygen

I hate reading stuff like this..

Valve blocks can be damaged by any ingestion of debris, even microscopic into ABC system... this might cause the valves to stick open causing the car to sit lower.

AH1W-COBRA

all the systems that were worked on are independant of youre suspension arent they?the ride height is controlled hydraulically and i have heard that if you turn on the ign while the cars suspension is elevated ie on a lift or jacks than it screws up the computers ability to return to its stored memory level position.it might be somthing as simple as rebooting the car and getting back to normal.

AH1W-COBRA

i knew i should have looked at the book before responding to this thread,abc dosent have its own hyd pump independant of power steering?

Oxygen

It's a tandem pump.. front side pumps for the ABC and the rear pumps for P/S.

I recently went through a whole mountain of **** with ABC, you can learn a lot about it from my detailed thread here: https://mbworld.org/forums/cl55-amg-...-pictures.html

carlosinseattle

I read your post right after I had taken my car into the shop. You actually made me feel like I did the right thing to take it in instead of trying to do it myself. I had a Infinity Q45A, which has a very similar system to this one. Actually the systems are eerily similar. The Infiniti system has a rear valve block that is a lot more hardy than the Benz. I know, because I did all the work myself. I changed out a valve block pump and strut in my garage.

I thought this system would prove to be at least as robust, but I guess I'm wrong.

6K in repairs in one month is hard to swallow. I have two sons in college and I feel stupid to be spending this kind of money on car REPAIRS.

Thanks for your feedback

carlosinseattle

Has anyone else had problems with a valve body or valve block? The part number is 2203200358, updated part #220 320 12 58

benztek97

The valve block in all actuality is not the problem. The problem is actually debris in the fluid. MB has a DTB (P-B-32.50/34E) about this problem. We usually flush the system per the wis instructions. Somewhere around 50% of the time this works, the other half you just have to replace the valve block.

carlosinseattle

Ironically it's been three days with no overnight sagging. I was tired of writing checks so I decided to take a few days to think about it. I noticed one night the car didn't really sag. So I ran a bar from a shelf across my trunk the last couple of nights to get an exact measurement of the drop.

No visible sign of a drop and the measurements don't lie. Less than a millimeter, if its only that much after sitting overnight for a couple of days I'm going to keep my money in my pocket unless I notice it drops sometime in the next few days. I told the mechanic I wanted to try flushing the system again before spending all that crazy money for replacing the valve block.

I'll keep you guys posted this weekend.

whoover

A flush is a good idea, but it should be done by the dealer along with the filter update:

Date: October 11, 2006
Order No.: P-B-32.50/42
Supersedes:
Group: 32

SUBJECT:
Model 215.373/374/375/376/378/379

Model 220.170/173/174/175/176/178/179, with Active Body Control (ABC) code 487

Model 221.171/176/179, with Active Body Control (ABC) code 487

Model 230.471/474/475/476/477/479

All Model Years

Vehicle Level Lowers on a Single Axle

If you receive customer reports in the above model vehicles of the vehicle's level lowering on a single axle on a single side after an idle time lasting from 1 day to one week, perform the new filter repair method as outlined in WIS document AR32.50-P-0025A instead of the previous flushing method.

Leveling complaints resulting from dirty ABC hydraulic fluid can be rectified just as effectively by filtering as by the conventional flushing method (replacing the hydraulic fluid). The new repair method is possible because the mesh width of the ABC filter was modified from 10 micron to 3 micron. Filtering is of no use if the ABC fluid is dark black or smells burnt. In such cases the hydraulic fluid must be replaced, reference WIS document AR32.50-P-0026A.

NOTE: Vehicle lowering is generally not the result of a malfunction of a suspension strut. The suspension strut can only be responsible for vehicle lowering if it has an external leak. This can be recognized by an oil fouled boot.

NOTE: The revised 3 micron ABC filter entered series production as of October 2005.

carlosinseattle

I'm going to call the dealer and discuss that with him tomorrow.