I have read around a bunch, about to tackle an issue on my 2004 SL55 AMG (R230/M113K).
New to this forum, I'm an automotive engineer (so I'm probably over-complicating this in trying to understand it instead of just swapping the part and moving on...lol).

Questions I can't find answers to:

1. what is this gold thing mounted to the side of my ABC/power steering tandem pump? (it is leaking) Is it a power steering pulsation dampener? (not ABC pulsation dampener)
2. I believe they are the same fluid, but do the fluids from both the power steering and ABC system stay separate or interchange/intermix? because I don't understand how a powersteering component issue is causing issues with my ABC system

symptoms:
ABC fluid low in reservoir
dash showing drive careful and red ABC warnings when fluid was low. (no warnings once fluid was topped back up)
all ABC works fine when fluid is topped off
no issues with power steering performance or fluid levels
green hydraulic leak coming from gold thing on side of the tandem ABC/Power Steering Pump


leak on my vehicle
The red arrow is pointing to the area where the leak is coming from

It’s the ABC pulsation dampener or damper. If it’s leaking it’s either loose at the banjo, or possibly bad. This unit quells the pump noise. The two systems are split, it’s a tandem
pump, and tandem reservoir deal. If you have low fluid, you have a leak ( which you have confirmed) but may have other issues.


My suggestion is to do a complete preventative maintenance on this system now before you regret it. Fluid, accumulators, filter, and hose visual check. the fluid is probably filthy.

Thanks. So, when I google ABC pulsation dampener, what comes up is the black spherical accumulators. So I'm confused on which one is the actual pulsation dampener.

I can confirm cdk4219's comment. I removed mine to do coil overs. It is just a hollow reservoir. If you are lucky it is just leaking O rings. I sold mine on ebay so leaks from the unit don't seem to be uncommon. If you can't find a replacement it may be possible to weld up crack in the old unit. I would guess it is just a typical low carbon steel.

It will be a bear to remove but I think it should be possible without removing the pump.

I had the same failure on my 2003 SL55 years ago. I concluded (in my case) that the support bracket failure (see pics) led to the failure of the ABC pump mounted damper (interestingly, NOT mounted in this position on later ABC systems). I did not find the damper available new, HOWEVER, it was easy to buy attached to a used ABC line. I used new banjo bolt seals IIRC.



Re-welded and ready to re-install

I seem to recall that removing and replacing the damper and bracket was NOT particularly difficult.
Hope that helps,
Chris

thanks guys. I noticed the bolt that attaches that black bracket to the gold thing wasn't even there....so the bracket wasn't doing anything...so probably put stress on that joint between the banjo and reservoir and cracked it. We will see this weekend when I take it off.