cmpcpro

Hey guys I don't have a humming noise to think the dampener is bad and the front suspension is all brand new genuine MB but I feel like I can feel every bump and crack in the road. The pump and fluid are about a month old too. As are the two accumulators.

g60wall

Return line accumulator, it's on the rear valve block.

cmpcpro

Thanks but it's about a month or two old

g60wall

There are 4 accumalor. Two large, one return line and the pulsation dampener. Also log you abc pressure while driving. Should not dip below 160 ever. If it does you have a bad accumulator and/or pump. The return line accumulator is the most expensive and the smallest. Not the rear accumulator under the exhaust. Then if that is not your problem the rubber on top of the abc struts is toasted and torn. Requiring strut replacement

cmpcpro

Okay, thanks! What is the best way to monitor it while driving? I just looked and he replaced two that were $130/ea and I remember them saying one was in the rear that caused the ABC light to come on if hitting a bump.. So I guess I should replace this return line accumulator. Can you tell me where it is? I assume this can be the cause and not give off a humming? The ABC pump is a month old, and it was just a rebuilt, but it wasn't a cheap rebuild it was a Meyle. Doesn't mean it's good I know.. However the old pump did give a warning of low pressure but this one hasn't.

Thanks again!

98'clk320

I replaced my anc pump on dec 28th remanufactured one no warranty and now its leaking smh,1200 out the window

g60wall

The return line accumaltor is connected to the rear valve block. It is in front of driver side rear tire. It is about $280 part. Get a iCarsoft i980, that will let you read all the benz codes and systems, and give you live data for data logging.

cmpcpro

Doh! Which brand did you get? I was going to go brand new because of the bad things I've heard about rebuilds but my Mercedes specialist friend said yes there are a lot of bad ones unless you go with a quality company rebuilding them. That's why we went with Meyle.

cmpcpro

Thanks for your help! I have the Mercedes Star Diagnostics but I just ordered the i980 too for the live information! Is replacing this rear accumulator as easy as the dampener? Thanks!

g60wall

Yea I would go as far as saying the return line accumulator is the easiest to do.

Mercedes-Benz Suspension Accumulator (Active Body Control) (ABC) - Genuine Mercedes 2203200415

the icarsoft doesn't do accusations or adaptions but its easy lets you clear limp mode. Its what I put in the cars my wife is driving just in case. or if i want to monitor IATS or Trans temp, etc....

bigmyself

Last only 3 months?
If MB remanufactured, there is warranty..

Sun

cmpcpro

Thanks so much! And you feel this would cause the car to feel all the bumps on the road without any humming noise? If the two cheap accumulators were already done I guess this and the pulsation are the only ones that haven't been. My last question, is there a good place with directions for this one? Thanks again!! You've been a huge help!

g60wall

No funny enough I haven't found one. There is another factor with the bumps. I would wait to get the iCarsoft i980 and drive around and get idea how our pressure holds. If it holds well, above 160 bar basically no matter what it's not the pump or accumulator. Another really big one is lower control arms!!!! Forgot to mention it if they go you really feel everything (through the steering wheel especially) only get Mercedes lower control arms, all the rest of the parts I would get from lemforder. Lower control arms and the ball joints of the spindle. I would inspect those(if they haven't) replace those asap. These three parts will make your car feel brand new.
lower control arm
front thrust arm
front ball joint on the spindle

g60wall

No funny enough I haven't found one. There is another factor with the bumps. I would wait to get the iCarsoft i980 and drive around and get idea how our pressure holds. If it holds well, above 160 bar basically no matter what it's not the pump or accumulator. Another really big one is lower control arms!!!! Forgot to mention it if they go you really feel everything (through the steering wheel especially) only get Mercedes lower control arms, all the rest of the parts I would get from lemforder. Lower control arms and the ball joints of the spindle. I would inspect those(if they haven't) replace those asap. These three parts will make your car feel brand new.
lower control arm
front thrust arm
front ball joint on the spindle.

g60wall

Just did this on the S65, with tie-rods. Car feels brand new

cmpcpro

Thanks but the front end is all brand new with all genuine MB parts. The only thing I didn't do was the tie rods as they seemed fine. The car feels like the tire pressure is super high and you can feel every little bump. It just seems way to stiff for a Mercedes. If I check it with the carsoft which will be here the day after tomorrow and see a pressure drop are you saying that could be the accumulator or the pump? What should it stay around? Thanks

cmpcpro

Also, could the pulsation dampener be going out and not cause a hum? How loud is this humming? Perhaps I'm just considering it normal.. thanks again!

g60wall

I'll take my car out tommorow and record the abc to compare it. My S600 has all New everything abc

g60wall

The pulsation dampener doesn't effect ride quality, what tires are you running? If the front end is all new. I would lean on your abc strut top bushing being bad than. With everything being new the return line accumaltor won't change ride quality as much as the big accumaltors did for your ride. We will wait and see what results of the logging are!

cmpcpro

Okay thanks! But if it goes low how can you tell if it's the pump or the accumulator? I don't really understand what these accumulators do but if the two cheaper ones are new that just leaves the return line one and the dampener.. maybe I should just do both..? Unless without a loud humming noise the dampener can't be bad? Thanks again!

cmpcpro

Thanks! I am running the Michelin Pilot Super Sports.. they are pretty pricey. 245/40/19 in the front. Is there an easy way to check the top strut mounts?

g60wall

The Accumlator are pressure resavoirs for the hydraulic system. If the strut has to perform a action and needs additional pressure to perform the task required the Accumlator supplies this pressure, also in reverse if you hit a bump and the system needs to eat excess pressure it goes there. The return line Accumlator helps regulate the pressure and shock that goes back towards the pump.

g60wall

Take the strut out and see if th rubber is cracked

g60wall

I don't know of any shortcuts on checking the struts! I just swapped full coilovers onto my S55 actually like it. It like being in sport mode all the time. I retro fitted sway bars on it too

cmpcpro

Ah, okay thanks! And I assume when they go bad they don't make any noticeable noise? Could these cars just ride rough because of being an AMG and 19" wheels? To me it just seems it should absorb more.. it seems over big bumps it's great but over the little things it's got no absorption