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hi there i have an ABC situation the oil is completely dark grean almost black on the ABC hydraulic side (reservoir) where the power steering still has fresh green oil
did i blow up an accumulator or has one of the solenoids failed ?does anyone have experienced that?
it would be obvious to diagnose it first but it's raining i didn't want to get wet. i thought of buying a new valve block and just replace it.
Don't start throwing parts or work at a problem you may not have. Dark ABC oil means it is dirty. A worn or broken ABC part doesn't cause this. Time and miles on the clock does. If it were me, barring any other problems, I'd do an ABC fluid flush and filter change. Pretty easy process. There are probably a half dozen threads on this forum on how to do so. Only thing of note is that you may or may not need a special tool to accomplish the task. Check the attached photos to see which type of ABC reservoir cap you have. That will tell you if you have the higher or lower style ABC return line and whether you need the tool or not. Here is a an ABC troubleshooting guide. Take a look at it before you do any ABC related work on the car. If you have any of the issues you MAY need to replace some parts. Do any parts replacement before the flush and filter change.
The tool is only necesaary if you have the newer (post 2006) cap which is on the left.
The tool is expensive ( ($150-$200) and only does this one task. However, doing the flush without it (if you have the style reservoir that needs it) is alot more difficult and a mess. I would have bought the tool but thankfully mine was the older style reservoir so I didnt need it.
Originally Posted by Fred Rezfield
hi there i have an ABC situation the oil is completely dark grean almost black on the ABC hydraulic side (reservoir) where the power .
Last edited by ShoeBoote; Apr 4, 2026 at 07:42 AM.
The ABC side of the pump is separate from the power steering side - they do not bleed into each other, so one side could be clean (i.e., the PS side) and the other side (i.e., ABC) could be dirty. Cheers Socks
Don't start throwing parts or work at a problem you may not have. Dark ABC oil means it is dirty. A worn or broken ABC part doesn't cause this. Time and miles on the clock does. If it were me, barring any other problems, I'd do an ABC fluid flush and filter change. Pretty easy process. There are probably a half dozen threads on this forum on how to do so. Only thing of note is that you may or may not need a special tool to accomplish the task. Check the attached photos to see which type of ABC reservoir cap you have. That will tell you if you have the higher or lower style ABC return line and whether you need the tool or not. Here is a an ABC troubleshooting guide. Take a look at it before you do any ABC related work on the car. If you have any of the issues you MAY need to replace some parts. Do any parts replacement before the flush and filter change.
The tool is only necesaary if you have the newer (post 2006) cap which is on the left.
The tool is expensive ( ($150-$200) and only does this one task. However, doing the flush without it (if you have the style reservoir that needs it) is alot more difficult and a mess. I would have bought the tool but thankfully mine was the older style reservoir so I didnt need it.
thanks for that
so i usually start a RODEO ? or PITCH or ROLL then with the CAP OFF (connected to a third hose to whatever into a bucket) let the oil OUT then manually add fresh green oil
i just finished watching the AGA flush tool video i think i won't need it but i might buy it that's like 15 liters of oil i can buy with that kind of money
Last edited by Fred Rezfield; Apr 5, 2026 at 03:40 PM.
They advise to do the PITCH actuation when flushing. I did the following:
1. Took the car for a 4 or 5 mile run just to get things warmed up suspension wise.
2. Get your STAR connected and ready to go and familiarize yourself with how to get to pitch mode as I dont think it stays completely connected goung from ignition off to started.
2. With the car off direct return line into a 5 gallon pail. I srltarted with a clean white bucket, this way I could see if any particulate was in the old fluid that got flushed out.
3. Get your 10 liters of Pentosin ready to go. Put a large funnel into the top of the ABC reservoir.
4. Have a buddy start the car. Once the car is running you need to pour Pentosin into the funnel as it pumps out.
5. Get into PITCH mode in STAR.
6. Add Pentosin into the funnel. You need to make aure that reservoir doesn't run dry. If you get behind, have your buddy turn off the car until you catch up then start the process again.
7. When you start adding in the last quart you can shut the car off. Be sure to stop the car before you add all your Pentosin in. Save some to top off the reservoir.
8. Remove the old ABC filter from the reservoir. Put the new filter in.
9. Reconnect the return hose to the cap. put the cap back in place.
10. Fill reservoir with additional Pentosin if needed.
11. Pour old fluid from the bucket into the empty Pentosin containers. Dispose accordingly.
Originally Posted by Fred Rezfield
thanks for that
so i usually start a RODEO ? or PITCH or ROLL then with the CAP OFF (connected to a third hose to whatever into a bucket) let the oil OUT then manually add fresh green oil
the self leveling tool does what exactly? and do you leave in the reservoir? you still need the cap off right?
Most important thing when doing a flush is to keep Pentosin in the reservoir as it pumps into the bucket. It's not like draining the engine oil. If the ABC pump runs dry it's game over for the pump.
If your cap is like the one on the right in the picture, YOU DON'T NEED THE TOOL. Don't buy that tool if you don't need it. It's not like you can use it anyway. It's designed for the cap on the left. It won't work. You can buy most of the Pentosin and a new ABC filter with the money instead.
Don't start throwing parts or work at a problem you may not have. Dark ABC oil means it is dirty. A worn or broken ABC part doesn't cause this. Time and miles on the clock does. If it were me, barring any other problems, I'd do an ABC fluid flush and filter change. Pretty easy process. There are probably a half dozen threads on this forum on how to do so. Only thing of note is that you may or may not need a special tool to accomplish the task. Check the attached photos to see which type of ABC reservoir cap you have. That will tell you if you have the higher or lower style ABC return line and whether you need the tool or not. Here is a an ABC troubleshooting guide. Take a look at it before you do any ABC related work on the car. If you have any of the issues you MAY need to replace some parts. Do any parts replacement before the flush and filter change.
one thing i did forget to mention actually i FAILED to mention since i am a huge failure is that i did do the flush a few weeks before so i was kind of surprised to see it dark green. and of course ABC failing like this; sagging in one corner (rear left)
Last edited by Fred Rezfield; Apr 6, 2026 at 03:03 PM.
I wondered what ABC symptom you had to prompt you to start this thread. Now we know.
Yes, a sagging rear corner indicates the rear valve block needs a rebuild. I suggest doing the rebuild yourself with a kit, typically $50. Doing the rebuild is easy, getting the valve block out is not.
I also had to rebuild my valve blocks. I cleaned out the solenoids and put the valve blocks into an ultrasonic cleaner. Everything was pristine, but my car still sagged after 24 hours. I have recently read that you also need to extend the springs that are connected to the solenoid.
Looks like I will have to tear apart my valve blocks again.
The ABC valve block has to be rebuilt. There are 2. One in front and one in rear. The O rings can be changed, but not necessary. The main problem is that there are 2 small springs in the valves that need to be extended. After years of use, they "dance" inside the valve. The ends of the springs become worn and they are not long enough to put enough pressure on the valves to close them. To rebuild a valve block should take approx. 4 hours start to finish. When looking at the valve block, there will be two valves that are the regulators. They control the height while driving. The other 2, which are the ones that have a tapered shape are the ones with the 2 stainless steel springs. If you look closely at them you will see that the ends of the springs look like they have been filed down. Simply stretch them out approx. 3/36" of an inch. These valves are shut when the car is parked and keep the fluid from reentering the reservoir. When they become too short to close completely, the car sags slowly after it is parked. In some cases, the ABC warning lights will not come on if you leave the ABC down while driving (both lights on the console off), but the car will raise when you put it in gear and will sag when it is parked. If after repairing the 2 small springs and the light comes on after driving with car raised, the other valve block's springs are wearing and need to be stretched. Replacing the fluid and flushing is recommended, but will not fix an ABC error. It is these 2 small springs that are your problem.
prior to that .... the [original] pump wasn't giving 180 bars it was a dying pump. prior to that i did have a bad accumulator (left rear) prior to that the front left block had to be replaced too but prior to that about 8 months ago i changed all the strut shocks.
prior to this i made a stupid mistake; i replaced the SL500 pump with a CL500 pump while the pump was good i had to use a power steering hose hoping it would work i don't think oil was really getting in the system. so i replaced the pump with the correct pump. i did a flush today. i did a RODEO.
i don't know it seems to be working but i can't get past 120 bars during RODEO (the car was coming up HIGHER on the left side than on the right side)
DYNAMIC TEST can't be done since it's not building pressure.
i hardly build up 150.
any suggestions? maybe i should drive it a little bit.
Last edited by Fred Rezfield; Apr 19, 2026 at 07:25 PM.
I also had to rebuild my valve blocks. I cleaned out the solenoids and put the valve blocks into an ultrasonic cleaner. Everything was pristine, but my car still sagged after 24 hours. I have recently read that you also need to extend the springs that are connected to the solenoid.
Looks like I will have to tear apart my valve blocks again.
The pulse dampener sits on a smaller block which includes an over-pressure valve. (Or is it simply the pressure control valve?)
IIRC this smaller block with its valve is available on eBay for $100 or so. I recall a thread from a year ago where the OP replace this pressure valve block to solve his problem.
The pulse dampener sits on a smaller block which includes an over-pressure valve. (Or is it simply the pressure control valve?)
IIRC this smaller block with its valve is available on eBay for $100 or so. I recall a thread from a year ago where the OP replace this pressure valve block to solve his problem.
were you referring to the thread resetting ABC ?
i managed to get somewhat of a consistent height where i would calibrate to a desired height then save though i was never able to get rid of the ABC yellow warnings.
the pulsation dampener is around 4 years old the only time i had to change pulsation dampener was when it exploded. i've done it twice on this car so far; the first time it was the original one and the second one was a used from junkyard so i decided to purchase a new one from pelican parts.
now i do have a bad banjo bolt eh? part number 0019902163, i have to replace that.
Last edited by Fred Rezfield; Apr 19, 2026 at 09:39 PM.
No, I am referring to something called the "ABC Suspension Hydraulic Pressure Relief Valve". It is the smaller valve block into which the pulse dampener screws.
There was at least one report of this pressure relief valve leaking and preventing full ABC pressure. For some (most?) cars it is part number 2203200858 and available on eBay with and without the pulse dampener for $100-$200.
Not trying to throw more parts at you, but personally I would replace that simple part before blaming the pump itself.
No, I am referring to something called the "ABC Suspension Hydraulic Pressure Relief Valve". It is the smaller valve block into which the pulse dampener screws.
There was at least one report of this pressure relief valve leaking and preventing full ABC pressure. For some (most?) cars it is part number 2203200858 and available on eBay with and without the pulse dampener for $100-$200.
Not trying to throw more parts at you, but personally I would replace that simple part before blaming the pump itself.
that's the "third" valve block ! no?
what do you call it? a pulse dampener?
I have been calling the 4 black air chambers accumulators on my 2003,4 SL500s. I stand corrected. This Air Chamber is a Pulsation Dampener.Mercedes often uses different terminology between:
EPC / WIS functional name:pulsation damper
Hydraulic system description:pressure pulsation damper
There is another pulsation dampener plumbed into the rear valve block. For the R230 ABC system, WIS and DAS do not use the box label name (“Air Chamber”). Instead, they refer to this component by its functional name: Pressure Pulsation Damper or Pulsation Damper – ABC. This applies to the center/rear-mounted small cylinder plumbed into the rear ABC valve block.
Source, Name Used OEM parts box, Air Chamber WIS (Workshop Manual), Pressure Pulsation Damper DAS/Xentry, Pulsation Damper EPC (Parts Catalog), Dämpfer – ABC (German for “damper”)
In this common diagram of the ABC system the pressure relief valve is 52B and an integral part of 52, which is part number 2203200858.
If the spring gets weak or the valve leaks you will not achieve 180 Bar. I don't know if the ABC pump regulates pressure, like a power steering pump does, or if 52B actually regulates the pressure. (If you know for sure, please let us know.)
In this common diagram of the ABC system the pressure relief valve is 52B and an integral part of 52, which is part number 2203200858.
If the spring gets weak or the valve leaks you will not achieve 180 Bar. I don't know if the ABC pump regulates pressure, like a power steering pump does, or if 52B actually regulates the pressure. (If you know for sure, please let us know.)
thanks i will try that i will try replacing the whole assembly as i have a really good condition unit on hand right now.
Just sold my '11 Porsche TurboS cab for an '03 SL55!
BTW, if in fact there is a lot of leakage at the pressure control valve (located in the rear of the LF wheel well), that could easily generate a lot of excess heat and darken the otherwise green oil. You might be able to get a feel by touch if the system is running very hot.
Also, I've had a number of bad valve blocks and have never found the rebuild kits to help.........when I pull the solenoids, all of the o'rings and TFE backup rings are in nice shape. Although I did hear of a case on this forum of an extruded o'ring that and in that case the rebuild kit fixed it. Don't bother with an "rebuilt" valve blocks that you see, particularly on eBay, because nobody has created a test rig to confirm that the solenoid blocking valves don't leak (Blocking valves trap fluid in the struts when car is off, and thus hold the height positions). I've found I'm better off with a new OE part (big $$), or if you are willing to take the risk of the Remove/Replace labor, then used ones on eBay are a good bet.
Let us know what you ultimately find.
BTW, if in fact there is a lot of leakage at the pressure control valve (located in the rear of the LF wheel well), that could easily generate a lot of excess heat and darken the otherwise green oil. You might be able to get a feel by touch if the system is running very hot.
Also, I've had a number of bad valve blocks and have never found the rebuild kits to help.........when I pull the solenoids, all of the o'rings and TFE backup rings are in nice shape. Although I did hear of a case on this forum of an extruded o'ring that and in that case the rebuild kit fixed it. Don't bother with an "rebuilt" valve blocks that you see, particularly on eBay, because nobody has created a test rig to confirm that the solenoid blocking valves don't leak (Blocking valves trap fluid in the struts when car is off, and thus hold the height positions). I've found I'm better off with a new OE part (big $$), or if you are willing to take the risk of the Remove/Replace labor, then used ones on eBay are a good bet.
Let us know what you ultimately find.
i know what you're saying but if there is a leak, and i have had lots of those ,you'll get a RED WARNING ABC right away
right now i get to drive a little bit then when i come to say a traffic stop then ABC RED Drive Carefully shows up. now this is a warning that ABC is no longer working if i don't have the shocks at their highest, i get ABC DON'T DRIVE CAR TOO LOW so it's dropping.
Just sold my '11 Porsche TurboS cab for an '03 SL55!
That Red ABC WARNING message light is usually associated with a bad accumulator(s). They are intended to maintain system pressure when the pump can't keep such as when you go over a bump. But, if you have low pressure then you could see the WARNING message at a standstill. You should have 180-200 bars at idle. If in fact its low (as per DAS) check the Pressure Control Valve that's aft of the LF wheel, or it could be a bad pump.
The Don't drive message tells you the car is too LOW. That will be visually obvious if in fact it is.........wheel will be way up in the wheel well. That could be an ABC Valve Block (The control valve not the blocking valve), a bad strut, unlikely, or a bad height sensor. You can test/check/compare the height sensors in DAS under the ABC section. If the ABC isn't working, then it's "deactivated", and if that's the case, the blocking valves automatically close and the car won't drop or drop very fast. So I don't think the it's not working scenario makes sense.
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