SL/R230: ABC1 VS ABC2
Thread Starter
Junior Member
Joined: Nov 2021
Posts: 49
Likes: 5
none
ABC1 VS ABC2
I am picking up a 2005 SL65 AMG.
Is the ABC1 that inferior in ride and handling vs. the 2006+ ABC2 system on these cars ?
I have a great mechanic, what can/should be upgraded on the ABC1 aside from regular fluid and filter changes ?
RichInCanada is offline
Is the ABC1 that inferior in ride and handling vs. the 2006+ ABC2 system on these cars ?
I have a great mechanic, what can/should be upgraded on the ABC1 aside from regular fluid and filter changes ?
RichInCanada is offline
Senior Member
Joined: Dec 2019
Posts: 407
Likes: 137
From: Houston, TX
2005 SL600
I've never directly compared the two, but a properly functioning ABC1 system works very, very well; well enough that I doubt you could tell much difference at all between ABC1 and ABC2 in typical driving. ABC2 is, I think, a technical improvement over ABC1 in that the design was refined and improved, perhaps faster microprocessors are used, etc., but I think the "ABC2" designation was probably more marketing than it was any substantial real-world improvement.
As far as maintenance/upgrades.......... when ABC was introduced, Mercedes claimed it was a maintenance-free system. But time and experience has proven that to be entirely untrue - every individual part of the ABC system is a maintenance item. Regular fluid and filter changes will certainly help to get the most life out of everything, but everything will eventually fail - the pump, the struts, the valve blocks, the accumulators, the pulsation dampers, the rubber lines, all of it - will wear out.
For a good overview of the opinions regarding ABC, from the Benz purists to to the Benz realists, read through this thread - you'll see my overall opinion in post #22.
In the time that's passed since I posted that, I've completed a coilover conversion for my SL600 (haven't installed the swaybars yet). I'll be posting a full review soon. But I'll say right now that I like it a lot, from both the perspective of handling/ride and reliability/peace of mind.
As far as maintenance/upgrades.......... when ABC was introduced, Mercedes claimed it was a maintenance-free system. But time and experience has proven that to be entirely untrue - every individual part of the ABC system is a maintenance item. Regular fluid and filter changes will certainly help to get the most life out of everything, but everything will eventually fail - the pump, the struts, the valve blocks, the accumulators, the pulsation dampers, the rubber lines, all of it - will wear out.
For a good overview of the opinions regarding ABC, from the Benz purists to to the Benz realists, read through this thread - you'll see my overall opinion in post #22.
In the time that's passed since I posted that, I've completed a coilover conversion for my SL600 (haven't installed the swaybars yet). I'll be posting a full review soon. But I'll say right now that I like it a lot, from both the perspective of handling/ride and reliability/peace of mind.
Last edited by brucewane; Dec 10, 2021 at 04:23 PM.
Senior Member
Joined: Dec 2019
Posts: 407
Likes: 137
From: Houston, TX
2005 SL600
I'll also add this - if ABC was truly worth its weight in superior handling, AMG would not have ditched it in favor of coilovers and swaybars on the SL65 Black Series. And I think those guys know what they're doing far beyond any of us message board ******* 
ABC lets you have both a very nice ride and very good handling, but if absolute peak handling is your goal, ABC is not superior to coilovers/swaybars.
ABC lets you have both a very nice ride and very good handling, but if absolute peak handling is your goal, ABC is not superior to coilovers/swaybars.
MBWorld Fanatic!
Joined: Aug 2020
Posts: 1,338
Likes: 366
From: Gretna, NE
'03 SL55 Black, '03 SL500's Aegean, Mars Red, Tazanite, Alabaster, '11 S550 Flint Gray
ABC1 and ABC2 are far more similar than different. There are a couple of changes that I see as a positive and one that is a downgrade in my opinion. The pulsation dampener is moved to the pump. This makes sense to calm the system at the source instead of downstream. Also, the strut position sensors are eliminated. This takes 4 potential points of failure out of the system. The downgrade is that the valve blocks for ABC2 are integrated units, cannot be rebuilt, and one bad solenoid requires replacement of the full unit. To be fair, Mercedes never offered parts to repair a block and always treated it as a unit, so it wasn't a service issue from their standpoint.
I you don't have any history of the accumulators being replaced, it is not a terrible idea to replace at least the main front and rear accumulators. At a minimum, check all of the high pressure lines visually. These would be pump to pressure valve, pressure valve to high pressure tee fitting, and the pressure lines from the tee fitting to the front and rear valve block P ports. If the rear line is original I would replace it when you replace the rear accumulator. It is very easy to replace. Unless the front pressure line looks bad, I would wait and combine its replacement with other service requiring dropping the front subframe. On the SL65, there are several reasons for having to do that.
I you don't have any history of the accumulators being replaced, it is not a terrible idea to replace at least the main front and rear accumulators. At a minimum, check all of the high pressure lines visually. These would be pump to pressure valve, pressure valve to high pressure tee fitting, and the pressure lines from the tee fitting to the front and rear valve block P ports. If the rear line is original I would replace it when you replace the rear accumulator. It is very easy to replace. Unless the front pressure line looks bad, I would wait and combine its replacement with other service requiring dropping the front subframe. On the SL65, there are several reasons for having to do that.
Super Member
Joined: Aug 2017
Posts: 520
Likes: 203
From: Scottsdale AZ
2015 SL550 & 2012 S550 4matic
And you might as well replace the ABC dampener and flush and fill the Pentosin with new filter too. I believe in ABC1 the dampener is mounted in the front driver side wheel well. The dampener is a nitrogen filled sphere with a flexible membrane that fails and the system will vibrate which is not good for connection points and rubber pieces.
Plenty of good documentation on these procedures on these boards.
Good luck with this beautiful car and put plenty of budget aside.
Plenty of good documentation on these procedures on these boards.
Good luck with this beautiful car and put plenty of budget aside.
