SL55/63/65/R230 AMG: ABC issues - reservoir overflowed & THUMP at startup
Thread Starter
MBWorld Fanatic!
Joined: Dec 2008
Posts: 2,396
Likes: 38
From: Bay Area, CA
2007 SL55 AMG
ABC issues - reservoir overflowed & THUMP at startup
Hey guys, I had something very weird happen to the car the other day. I came home (in another car) and spotted a puddle of fluid under the car and found it to be ABC fluid. Upon further inspection I noticed the reservoir overflowed. I had used the car earlier in the day without any issues. I know this is typically due to a blown accumulator. I sucked some fluid out and adjusted the fill level to be right at the top marker (car off line) and started the car and let it idle. The fluid level over a few minutes of idling was a little below the bottom marker (car running line). At this point, everything was operating normally, the car lifted and lowered correctly, pump was running quietly at idle, no lights on the dash. The only thing that was out of place was a loud THUMP a few moments after I started the car. The sound vibrated through the chassis and it felt like it came from under the drivers footwell area, however I could be wrong about this because I was sitting in the drivers seat when this happened.
I let the car sit for a whole day and checked everything again. The fluid was in the center of the top marker on the dipstick and the car had not sagged at all. I started the car again and a few moments later there was the THUMP sound again.
NOTE: I have an 07 model with ABC 2
Has anyone experienced this before??? I was going to drive the car around to see if I get any dash messages going over bumps, but the thump has me concerned there could be further damage done by driving it. Any help would be greatly appreciated!
I let the car sit for a whole day and checked everything again. The fluid was in the center of the top marker on the dipstick and the car had not sagged at all. I started the car again and a few moments later there was the THUMP sound again.
NOTE: I have an 07 model with ABC 2
Has anyone experienced this before??? I was going to drive the car around to see if I get any dash messages going over bumps, but the thump has me concerned there could be further damage done by driving it. Any help would be greatly appreciated!
Thread Starter
MBWorld Fanatic!
Joined: Dec 2008
Posts: 2,396
Likes: 38
From: Bay Area, CA
2007 SL55 AMG
I just wanted to provide an update on my fix for anyone who has this issue in the future. I replaced my rear accumulator and solved the issue. On ABC 2 cars, there are 3 accumulators in total. One is on the pump that is known as the pulsation dampener. Then there is one accumulator on each valve block. I inspected both and found that the front had been replaced by the previous owner. I bit the bullet and replaced the rear and the issue went away. I purchased 2 tools for the quick release fittings for the rear lines in order to take it apart. I will follow up with pictures at a later date.
Newbie
Joined: May 2022
Posts: 1
Likes: 0
R230 SL 500
So...any pics? Would you also happen to have a link to the tools you used for the quick release fittings? I'm going to Google, but it never hurts to ask 
.
Nevermind, I found a DIY guide:
https://www.youcanic.com/wiki/quick-...-mercedes-benz
From that site:
"Mercedes-Benz recommends using a tool 230589013300 or 221589013300 to disconnect the quick disconnect coupling on the ABS (they mean ABC) lines. Another method is to use diagonal cutting pliers. Not to cut the ABC line but to release the connector. Another option is to use a 15mm bike pedal wrench."
ECS Tuning has both of the tools in stock
Aftermarket: https://www.ecstuning.com/b-genuine-.../221589013300/
Genuine Mercedes: https://www.ecstuning.com/b-genuine-.../230589013300/
.Nevermind, I found a DIY guide:
https://www.youcanic.com/wiki/quick-...-mercedes-benz
From that site:
"Mercedes-Benz recommends using a tool 230589013300 or 221589013300 to disconnect the quick disconnect coupling on the ABS (they mean ABC) lines. Another method is to use diagonal cutting pliers. Not to cut the ABC line but to release the connector. Another option is to use a 15mm bike pedal wrench."
ECS Tuning has both of the tools in stock
Aftermarket: https://www.ecstuning.com/b-genuine-.../221589013300/
Genuine Mercedes: https://www.ecstuning.com/b-genuine-.../230589013300/
Last edited by YeaItsJosh; May 10, 2022 at 01:03 PM. Reason: found part
