JPhamily

So earlier today after getting my haircut, I walked back to my car and notice there was a puddle of fluid on the front driver side right under the fog lamp and I already knew what it was... A couple months ago one of my abc lines ruptured at the same place and I had that replaced. After noticing the puddle, I started up my car and sure thing there was the red abc light "drive careful". I popped open my hood to look and see where it was coming from and noticed it was coming out of the big tank... As I was standing there, the fluid started shooting out of the two holes from the dip stick! It sprayed out for a good five seconds. I called a shop and asked the guy and I told him how I got one of the lines replaced not to long ago and he said that it sprayed out because there was a air pocket in the system. He told me to just top it off and it should be fine. So I drove home and the abc red light wasn't on anymore but it would only pop up very quick whenever I go over bumps. It did this before too but only when I went over big bumps, now it happens on every bump. The car is very bumpy now too. I'm guessing my accumulators went out? Someone help me out please.

BlownV8

Warning lights going over bumps is probably the accumulators.

Crissus

Right and that explaines why it was overflowing. Because that nitrogen in the accumulators/spheres is compressed at way over 100 bar. Once its set free it can be dangerous in the system.
I would replace all spheres/accumulators. You can get 2 of the 4 types in the aftermarket cheap from the OEM "Cortecco".

NRL

In my case it has a burbing sound, when starting, then when driving, you can feel all the tiny vibrations off the road, and a groaning supercharger like sound. When it first happened, I saw steam or gas coming out of the dip stick holes.. hopefully that was nitrogen.

In my case, it should be the "pulsation dampner" on the passenger side, near the wheel well..

gonna update the "Accumulators" thread..
Just finished up replacing the 4 Accumulators last night, took lots of pics on where they are and how they look and how to remove some of the difficult ones..
Takes lot's of patience on doing it without a lift only only with Jack stands and jacks..

Along with the Accumulators, I want to get the two special tools that can handle removing the hydraulic cables/connectors so in the future I can just remove them (after the bleed process) and have new ones made..

JPhamily

Thanks for the reply guys, Im going to replace all accumulators but Im a bit confused. Are accumulators and pulsation dampeners the same? Which are the two up front, the one right next to the valve block and the one near the passenger front wheel. I also know there's one in the rear where the fuel filter is. Where is the forth on? Im planning to replace all of them, just thought there was three but Crissus says there is four.

NRL

Technically they are all accumulators, but have official names for them:

air cell, pulsation dampner..

I just finished swapping out 4 of them myself DYI, took me about a week working on it a bit at a time..
They are not all the same. The easiest one to get to is the Front Accumulator, take the driver side wheel off, remove the inner wheel well lining and you'll see it front cavity.. That one was the easiest to do for me.

The front one is the same part number is the rear accumulator, both of them the largest accumulator compared to the other two.

The other two are unique, found one near the fuel filter/ pump. This one was easy for me to remove compared to the other one which is on the passenger side near the front wheel underside area. That one was the hard one to remove because they are on rubber mounts so you can't get enough torque to get it off.. you'll need to hold it with a cresent wrench hold the metal plate where the valve block is connected to and carefully unsrcrew it off.. I had to had a pipe extension over my thinset 24mm to get enough leverage to get that one off..

The rear accumulator is underneath the passenger side muffler, you have to undo the two 13mm bolts holding the muffler, and part of the heat shield but before you do, undo the rubbermounts that hold the exhaust up and a few other items.. this is needed so you can get that big accumulator out and put the new one in..

In my case, it was the pulsation dampner located right near the front passenger wheel, you can see it in a indent once you remove the wheel. Symptoms were no error codes other the when the nitrogren membrane must have broke, lost pressure, 190 psi afterwards, no leaks, rough freeway, just no damping in the suspension.

It finally died and I think it was because the dealer had over torqued it on there. I measured 60+NM before it would unscrew!

Just finished up today, just did a few tests, checked and topped off the ABC reservoir making sure it's right on the dip stick marks. Raised it a few times, no errors, no burping, no groaning...

It can be done DYI, but you need the right tool set of all kinds: 8,10,11,12,13,17,24mm wrenches / flare nut wrenches, thin set wrenches (that 24mm), sockets, long extentions, interchangble torque wrench for torque flare nuts to 50Nm, hydraulic jacks, jack stands, more safety jack stands, borescope! and more..
I'm getting a garage portable lift for sure soon.

JPhamily

Nice, good to know you did it yourself because I'm the type that doesn't mind getting under the car and getting my hands dirty. Ill wait until you update your thread to get the parts number and step by step. Until then ill just have my car parked and not drive it.

NRL

I'm done.. With the Jacks and ramps around, I've decided to work on two other items I've been wanting to refresh and finish up: fuel filter and the famous transmission harness o-ring slow micro wicking from pan thru harnes to tcu box leak. Evacuated the transmission oil going for pan removal..

Here are the Order Details for the CL65/ CL600

• AIR RESERVOIR (Driver Side Front, Passenger Side Rear Near Mufflers)
  
  • Part Number Item Price Core Quantity
  • 2203270115 $ 146.25 $ 0.00 2

• AIR CELL (Pulsation Dampner Accumulator)
  
  • Part Number Item Price Core Quantity
  • 2203200415 $ 140.25 $ 0.00 1

• AIR RESERVOIR (Near Fuel Filter/Pump Area)
  
  • Part Number Item Price Core Quantity
  • 2203270215 $ 138.75 $ 0.00 1

JPhamily

Thanks a lot man. It should be the same for CL55 right? Also, I've never heard of the "famous transmission harness o-ring slow micro wicking from pan thru harnes to tcu box leak" before. Please tell me more about this. My car has a slip in first and second gear now... First step is to do a transmission flush but I had one done myself last year... Second step is to replace the transmission valve block..

tusabes

Here is the transmission fix to avoid fluid wicking into the wiring harness

https://mbworld.org/forums/cl-class-w215/536506-ecs-tuning-722-6xx-automatic-transmission-wiring-harness-spacer-kit.html

leodangelo

Thanks for the great information. I believe I have an issue with the dampers/accumulators in my CL65. I've had the 'super charger whine' for over a year. I've brought it to my mechanic twice now asking about it and he says 'These cars make noises and that is the turbo', however, it did not used to do this... So, my questions:

1) How do you verify that this is an issue (I'm assuming using DAS)? What is the 'normal' ABC pressure?
2) Is there any way to determine which of the four dampers/accumulators are the issue?
3) Any chance you have lowered your car? My 'issue' started soon after I lowered my car with links (which I assume raises the overall pressure in the system)?

Thanks in advance for the help!

-LeoD

NRL

When I was removing them one by one, I tried the method mentioned in another thread or I think it was the Edmund's review on the CL65 that mentioned you can take a small screw driver or tiny straw and stick it in the Accumulator hole, and if it drops in deep then the membrane has ruptured.

I tried that one method on all the ones I removed and none of them were "broken" using that method. Maybe the rupture of the nitrogen membrane has to be extensive for that method of testing whether it's bad. My rupture might have been tiny to the side of the membrane and not completely disintegrated.

In my case, the groaning "super charger" sound is gone after the replacements. I really think it was the accumulator called the Pulsation Dampner that Damps out your ride (like on the freeway) from tiny vibrations located near the front passenger side wheel well. I also read the pressure using DAS and it was consistently at 190 which is low and probably making the steering pump work extra hard to keep the pressure up high as possible. The pressure now is at 200.

I've read from other threads there is a "bounce" test you can do determines if the other Front accumulator, or Rear Accumulator is bad.
If it bounces with the car turned off, front or back, then the accumulator is bad.. normal behavior is it should not bounce.

Not sure about if it's bad for ABC if your car is lowered. My own reasoning is that it does not. When at the lowest setting, most of the fluid in the ABC system is in the reservior, especially when it's off, and when you have the suspension at it's highest setting, most of the fluid in the reservoir is not there.. Leading me to think that pressure is highest at highest suspension setting. But then again, the ABC self bleeds in 5 minutes when you turn off the car.. and after awhile, the ABC Reservoir level rises.. about halfway.

NRL

That's the one I'm working on now..in the evenings.
In my case, the leak is really slow, super slow, like an inch of fluid in 1-2 years or more.. leaks into the tcu box, coating but not harming the electronics. I caught in time when EC was tuning the TCU and dumped it out.

You have to worry about it when it overflows though, which hasn't happened to me yet..

JPhamily

Would this be the correct part for front and rear Air Reservoir?

http://www.ebay.com/itm/Mercedes-W12...-/151119481756

awiner

No. It looks like this:

mbcoupe57

these accumalotors are often overlooked as culprits with theABC sys...MB has been using them on every vehicle with self leveling suspension (standard equip on wagons rear axle) since the early 80's at least..the tmodels had one mounted above each rear wheel ..the car seemed to tolerate one blown cell with barely noticeable bounce,,, when both were bad the car was somewhat hairy to drive due to the strut being essentialy non compressible lol..most owners esprcially women thought the ride was normal... i blame the somewhat premature cell failure on models made after 2000 on the synthetic green brew MB specifies ..the earlier models lasted well past 200k mi ...btw i use MB power steering fluid in the ABC in my 03 SL55 and every ABC repair/service i perform on customers cars with a qt of Lucas power steering treatment which is cheap insurance INMHO

biker349

interesting insight. are you a mb tech? i just got my bill from dealer and there are many codes 210129 cpsc. does anyone know what this means?

biker349

okay, i found out. the numbers are the tech, the cpsc means warranty work, or so i've been told.