Thought this may help someone out especially if you’re anything like me (super paranoid about the ABC system pressure)

Quick snapshot of symptoms:
1) Loud “pop” from front drivers side at start up and fluid leaking from reservoir dipstick.

2) Noticeable buzzing/groaning when rpms drop when coming to a stop (sounds like a dry pump or air in pump)

3) Intermittent high pitch whine between 40-55 mph

All issues resolved with accumulator (one behind drivers side bumper) replacement

Quoted: $1,600 labor only (Indy) & over $6K stealership recommending changing pump, entire valve block and other nonsense…smh


I apologize for video quality as I was working one-handed!

Here, I used a chain wrench (my rubber one wasn’t long enough); which I highly recommend cause it locks in place.

*Note at the 2:08 mark I attempted to screw in the new accumulator without inserting the little plastic piece—I noticed and in part 2 I made sure to insert.

https://youtu.be/sf9l_zgrAjI

Here’s part 2–brief look at both accumulators

https://youtu.be/HFbYJnoNi-E

Here’s part 3–accumulator screwed into block

https://youtu.be/nyLNeAMhkWI


As you noticed there was virtually no fluid loss or pressure which were my 2 biggest concerns.

I did use 6-ton stands on the front. When I went to jack up the back there seemed to be too much weight for the jack so I just decided to take a chance and leave the back tires on the ground (back passenger side slightly supported by scissor jack)

I also took heed to recommendation by lionsfan54 who mentioned unscrewing the ABC reservoir cap. I did this but did not actually open the cap/filter housing. Not sure if it actually did anything but it made me feel good psychologically (kinda like I went an extra step to relieve any pressure on that front side hydraulic circuit)

All-in-all while a bit unnerving considering it’s the ABC system, the job was easy (less than an hour).

Really hope this helps! This forum has been the best find for me and I’m happy to contribute!

Total cost-
Front accumulator from FCPEURO- $166 (lifetime warranty)

Chain wrench from Harbor Freight-$15 (lifetime warranty)

Saving thousands with the help of my MBWORLD family-PRICELESS

 

This post shows how the alternate universe can exist where "OMG I bought an S600 and something happened with the suspension and it was a $6k bill." Yet it was an under $200 DIY repair. I think MANY things on these cars fit into this category. So when reading old threads when the cars were used but newer (MUCH more dealer service), you really need to understand the particular failure and not just flip out because some guy had a crazy repair bill on his ABC.

 

Well said!

The keyword is “understanding” because just going by what some tech says is NOT understanding.

As I mentioned the symptoms varied and it can be difficult to not just take the so called trained MB “experts” word for it, but what makes this forum so great is you can actually get information to better understand what’s happening.

The folks who owned these cars new or early pre-owned were at the mercy of the stealership.

 

Yes and I think this is another reason why, at least from my perception, cars like this magically seem to become more reliable than they were earlier in their life. Obviously the other half is just sorting out half-baked design issues that required hardware/firmware revisions. Those things typically settle out as a car ages. I'm not saying everything becomes a Camry, but I'm more convinced than ever that a good DIY approach can make 85% depreciated examples totally reasonable to own and operate. A lot of us already knew that but I just like to point out the obvious.

 

well said! and great work, i replaced it a couple of months before on w216 cl550

i have a question if you don't mind, any ideas if the 08 w216 ABC valve block can be rebuilt or should i replace the whole valve block? i have oil and pressure leaking from the longest ones

see attachments if it helps

thanks in advance

​​​​​​​

 

Others speak of replacing O-rings in valve blocks. I have not done this operation. Never needed to.

 

​​​​​​​A question mate, I have a CL550 c216 year 2007, I want to replace the front and rear pressure accumulators. The front one behind the driver's wheel arch, do I loosen it and tighten the new one, do I tighten it very hard? And for the rear one it has 3 nuts, how do I remove it? From the bottom of the vehicle? Or from the trunk? It is the most difficult.

 

I did this a few months back. The video posted above is helpful for the front. Yes, front, loosen it with a chain wrench. Be patient as it is hard to get the chain wrench setup in the tight space. Just unscrew it and take it off. When installing the new one, be very careful to line it up correctly as it is a heavy part, and easy to damage the soft aluminum valve block it not dead on straight. I believe the tightening spec is 50nm, but impossible to get a torque wrench in there. I just tightened as much as I could, then got a 23mm spanner wrench to tighten at the base. The rear...ignore the WIS instructions. Pull back the heat shield slightly to expose the 3 bolts from below. With extensions you can screw out the three bolts and then remove the part from above. When reinstalling, it helps to have someone hold the part from above for stability when screwing the line back in. The whole thing seemed daunting at first, but was quite easy in the end.

 

Thank you very much for your detailed response. You have helped me a lot, I didn't know how to remove the one from the trunk hehe. Thanks again! Regards

 

HI everyone,

I have a leak on the valve block, O ring that has ripped.
I'm trying to replace the o ring but its hard to reach.
Hope to get some help. how do process on this bolt with the o ring leak

the bolt that has an ripped o ring

ripped o ring

ripped o ring

ripped o ring

hard to reach, blocked by metal bar