wuyichao

Hello,
I have a 2004 SL500 and it has 40000miles on it.

I took my car to a technician due to ABC failure. Then I was told that ABC oil has never being changed for the past 8 years. So I called MB dealership service adviser and he replied "it's not necessary and it's not written on the service booklet".

So my questions is, does ABC oil have to be flushed regularly? Is it listed on any MB document? Thanks for any inputs in advance!

jay

Stoofpilot

My Indy uses a pipe filter to test the color of the ABC fluid. If its green, he says it's good. In any case, I have an 04 with 36000 miles and am thinking of changing the fluid from just a precaution standpoint.

Comments/suggestion?

rune solem

I have checked the manual, and the only thing that is mentioned are that the owner shall not check the abc oil level.

If you get a warning in the cluster, you shall go to the workshop.

That's all it says in the manual.

bha

MB doesn't have a recommended service interval for ABC fluid.

According to MB, the system is filled/sealed "for life" and doesn't need to be flushed. Just like MB transmissions. The problem is, they don't specify whether "life" means yours vs. the ABC pump's life

If you haven't changed the fluid (or have records of it being changed) in the last 3-4 years, change it now.

Preventive maintenance is cheap, but repairs are expensive. Sure, you don't need to change the fluid but you can also "technically" run your transmission on the same fluid forever. Till it dies, that is Why not change it for a couple of hundred $ and know you'll have a great system for years to come?

Also, MB changed to a smaller micron filter in later years with the SL. So they obviously thought the dirt in the system needed to be filtered to a smaller size, in order to prevent valve blocks from getting gummed up. If you haven't changed your fluid, you still have the old filter.

I picked up a filter for $30ish and paid $11/qt for the fluid. Even if you don't want to buy 11 quarts of fluid as recommended by MB for a "full flush", 5 quarts would get you a mini-flush and nice clean fluid throughout the system. I'd do 5qts+filter at minimum.......

Neander

Without knowing what the ABC failure was, it's hard to accept the statement that the failure was due to the fluid not being changed for eight years. What specifically was wrong with the ABC system?

It's hard to understand what would cause the hydraulic fluid to go bad. If you do a web search on 'hydraulic fluid deterioration,' you will find that the primary cause of deterioration is contamination from entrapped air and water, along with particles of metal, rubber and dirt. As long as the system remains sealed, there shold be no problem. In fact one source stated that "often, the simple act of replenishing the system with fluid, is the major cause of solid particle ingress."

Maybe it's best to leave the fluid alone. I'm just sayin....

Stoofpilot

Where is the small filter located?

Thanks

grane

If you have a component failure only a flush is recommended. In a stable system a flush can do more harm than good.

Otherwise I change the main ABC filter only at 50k miles according to instructions from a non USA AMG abc ingeneur. If the fluid is green and all the lines are ok, no components leaking, just replace the filter. Yes the new filters are 3-4 microns. They have a metal cage to hold the filter fleece or whatever intact under high pressures so don't think you have a lot of particulates or shavings if it sparkles. Don't overfill the system! Make sure everything is wiped off and squeaky clean before attempting this at home.

The other thing I do is to run my ABC and transmission in Comfort setting and turn off aBC Sport, raise the ride height one LED under winter conditions as recommended in the OM. I also use winter snowflake tires that have more "give" in the cold. I have this silly theory about this but I'll keep my mouth shut until I can verify it.

wuyichao

very helpful comments, thanks guys!

Stoofpilot

Where is the ABC filter located?

pleeson

Inside the fluid reservoir, in the left front part of the engine bay.

jnash

Every two years regardless of milage. ABC fluid absorbs water like break fluid does.
Read this, you will have to do a google translate on the site.
http://www.exclusiv-automobile.de/ww..._Fahrwerk.html

Sky Pilot

It's connected to the cap on the fluid reservoir, next to the dipstick. The cap has a hose connected to it externally. If you remove that cap, the filter is connected to it, and sits inside the reservoir. It is cylindrical in shape.

fxrs1955

The filter is easy to change, be sure and cover the tank when you do.

Riverflyer

I picked this info up from another thread. I am in the process of buying an SL55 so have been reading up on the issues. Found this piece very useful and informative.

https://mbworld.org/forums/sl55-amg-...t-article.html

Mercedes*Benz ABC Suspension
Our*company has specialized on the ABC suspension for years.
We*diagnose*,*repair, and*replace*all components in the ABC suspension.
For*questions please contact our phone number. We are happy to help and assist you with tips and tricks that work.
What*is the ABC suspension?
The*ABC suspension is an electro-hydraulic active system combined with a coil spring.*
The*Active Body Control (ABC) can compensate within milliseconds to the rolling and pitching movements of the body when starting, braking and cornering. The ABC is thus superior to air suspension systems.
Care of the ABC system:
The*ABC suspension has a gotten a bad reputation because many owners do not maintain it, and critical components become damaged – eventually destroying the whole system. Regular maintenance results in an ABC suspension with the same life expectancy of the rest of the vehicle. Below you will find some hints from our experience.
If it is operated for years with the original hydraulic fluid, or after this fluid has become dirty, then many if not all of the components of the ABC chassis can be destroyed. OR if it is operated with low fluid levels, the owner will have the same result. This includes the hydraulic pump, struts and valve units.
You*can easily check your oil quality using the dipstick from the reservoir. This sits next to the fill cover which contains the white filter. Take a white lint free towel and pat the oil from the dipstick onto it. Clean oil is green, light brown in ‘fair condition.*IT SHOULD BE REPLACED BEFORE IT BECOMES DARK BROWN OR BLACK.*If it is very dark brown or black, replace it immediately (or be prepared to replace expensive components).
The*system uses about 15-16 liter of*Pentosinöl*(A00198924003-10, or Pentison CHF 11S). To replace you will need about 10-12 liters. This will replace MOST, but not ALL the hydraulic fluid, as some will remain in the individual spring reservoirs.
But, that is not a major*problem. The large amount of new fluid mixes with the small amount of old fluid. You will also replace the filter in the ABC reservoir with the new 3mm filter. This new fine filter will clean the resulting fluid mixture. After about 750 -1500 miles you should once again flush/replace both the Pentosin fluid and the 3mm filter. Then you should end up with only clean/green fluid in the system. (*Anleitung_Spülen*pdf.*)
In one of*the*pictures you can see an additional filter, which we developed. This*magnetic filter*is*specially designed to trap metal abrasion particles that can come from components of the ABC chassis. These metal shavings are caused when old ‘dirty/abrasive’ fluid flows through the ABC hydraulic pump, causing mild to severe erosion of metal. This magnetic filter removes any future metal abrasion or metal chips from the fluid, thus protecting the whole system (the fluid is repeatedly flushed and cleaned with every circulation through the reservoir).
Once metal shavings are created, they can infiltrate the entire system, making it necessary to disassemble the entire system and clean by hand!
The installation of the magnetic filter will help prevent this from happening. With the crystal clear case, as you open the hood, you can readily see and check the color of the ABC fluid and observe whether any metal has been collected by the filter. The filter is washable, so you make a one-time purchase. In the rare event that somehow something gets broken, all parts can be ordered individually.
CLEAN OIL is important for the long term durability of the ABC system
In*the*first picture you can clearly see an ABC pump that has run 120,00 miles in the clean ABC system looks like. In the pictures below, the pump has been running about 48,000 miles, and the fluid was very dark brown. The metal debris in the oil has produced fluid that is the equivalent of liquid sandpaper – which has rubbed and damaged everything - with every mile that was driven. Moreover, with this abrasive fluid, more friction occurs in the system, especially in the ABC pump. High friction means more heat. On some occasions pumps have become so hot that they overheat and glow! When this occurs, EVERyTHING DETERIORATES your fluid becomes progressively worse and begins to smell like burnt oil.
If*the Pentosinöl in the ABC system is renewed every 15 to 30K miles, or every ~3 years, depending on load and driving style, the ABC system should last for 300,000 miles or longer.
This longevity has been proven by our own car and the maintenance we have done on it. This car is a*W215 CL 65 AMG V12 Biturbo, and after about 6K to miles the fluid begins to turn brown. After 12K miles it is dark brown.
For*vehicles with less engine power, it may take longer. But we have found the fluid usually starts to turn a dark brown to black color after ~18-25K miles. For vehicles that are have not had adequate service to the ABC system can change color even faster after the first flush/change.
We have driven our*frequently used 2003 W220 S Class long version S55 AMG Kompressor ~250K miles. We have changed the ABC fluid approximately every 18K miles. All suspension components on this car are original except for 2 dust covers for rear shocks and a pressure hose to the right front strut. AND, the*ABC pump from our vehicle had after all these miles is still ~190 Bar (~2,850 PSI) at operating temperature.
Our latest acquisition an S Class W220 S65 AMG V12 Biturbo long version 25K miles. The Pentosinöl was black as tar.
We*had to disassemble everything clean and repair many components.
At*this point, it is important - both for vehicle owners with ABC suspension (and Mercedes shop foremen and those who want to be) – to remember that the Pentosinöl has properties similar to brake fluid. They are both hygroscopic meaning they absorb water, such as from the air. Therefore, it is IMPORTANT that the Pentosinöl is replaced after a maximum of 5 years to prevent corrosion in the suspension components. (here they state this time interval is also recommended by Mercedes Benz – certainly it is for brake fluid, but not clearly stated for ABC fluid as far as I know).
For this reason alone, this fluid is*not*maintenance free as is always claimed by the MB dealer. You can check about the hygroscopic effect under brake fluid at Wikipedia.
Pentisol is hygroscopic, like brake fluid it absorbs moisture and deterioriates!*
We*found one incident where a SL 55 AMG was stored in October and brought out for driving in April. During the winter, the pistons had rusted in the ABC hydraulic pump. When first started, the pump was destroyed and there was, within seconds, a red error message on the instrument cluster.
"ABC defective please visit workshop". If that appears, the pump pressure is below 100 bar. At any pressure of 99 bar or lower, this red error message appears and the car DEFINITELY should not be driven further.
ABC pumps and systems are ONLY destroyed by bad fluid!!
The ABC pump is lubricated by the Pentosinöl and 200 bar pressure which it produces. This fluid passes through micro sieves and around and through very small passages to the main shaft and main bearings. Contaminated fluid first contacts the screens. These become partially plugged, and as a result the main bearings are inadequately or not at all lubricated. Then, the pump starts making bearing noise. When that occurs, if you then press the ABC button for lifting and your vehicle goes up.
During*the raising of the vehicle the ABC pump is quiet for a short time. When it reaches full height, the pump becomes loud again!! Reason for this is that during the lifting operation, the main shaft is pressed under load into the main bearing, so the ABC pump for this moment is quiet. When the vehicle is at full height the load is no longer holding the main shaft to the bearing. Thus, the main shaft is rattling in the main bearings because the fluid pressure/film is missing.
IF*the wear of the shaft and bearing is advanced, the pump is constantly loud.
It*also happens that if the oil supply rapidly goes to zero, then the main shaft overheats the main bearing and they VERY RAPIDLY wear on each other. The pump is ruined.*In*these cases, repair is not possible. The pump housing is useless because the bearing seats are damaged in the pump housing and new bearing not available.
The most common cause of pump damage is the overheating of the pump through abrasive fluid. The metal debris in the oil is like sandpaper between the rotating parts.*Due to*the poor FLUID, higher friction results and the pump over-heats and is destroyed.
In rare cases, the*pressure housing may crack, thus the pump leaks and fluid level drops dramatically. Also, the breaking off of the plugs from the pressure housing can cause this catastrophic loss of fluid and pump destruction.
Consequences of inadequate care and maintenance of your ABC system:
Dirty fluid will first slow the ABC hydraulic pump (plugged sieves). Many errors of the suspension result from the insufficient pump pressure. If the pump pressure of 200 Bar drops to about 160 Bar, the instrument panel will display in white/black: "ABC defective, please visit workshop".
If*you then continue to drive the vehicle and the pump is working, the warning message will soon appear in red, (the pump pressure has dropped below 100 bar) and the ABC system goes into limp home mode. It closes the shut-off valves in the valve unit, so that the vehicle does not fall down. Your vehicle drives as if the shock absorber is defective.
With a red error message it is best to stop immediately and have your car transported to a service facility. If your ABC pump fails suddenly damage usually occurs throughout the system, as the fluid brings the chips with it. Continuing, the chips are distributed with the still small pressure in the system. That would be the worst thing that can happen. Your ABC suspension would then actually be a total loss. Mercedes Benz then recommends that all ABC suspension parts be replaced with new components. The ABC pump is a precision high pressure hydraulic pump that generates 200 bar, so everything must function precisely and with VERY low clearances. A metal chip left in the system is sufficient for the new ABC pump*to*be destroyed. Flushing the system in place brings no guarantee that it is clean, due to the branches(nooks and crannies??)*throughout this complex system. A complete disassembly, flushing and cleaning by hand is the ONLY possible way to avoid future problems from such debris. Any other approach is Russian Roulette.*
The cars we have serviced or repaired over the past years is proof of our approach. They continue to run well and do not return for ‘repairs’, only service.
Do you have questions, problems with your ABC suspension? Give us a call!
Phone*: 03877-56 26

vtvette

Two worse things for these cars:

1) Not driving them on a regular basis
2) Not changing the fluids

I change my ABC fluid and filters every 20,000 miles.

At 100,000 I changed my accumulators and rebuild by valve blocks as preventive maintenance.

I am on the original pump and all original shocks. No weeping or seeping of any kind from any of my lines/hoses. Car rides like brand new.

2005 Sl55 104,000 miles.

Tomcruiser

Thanks vtvette for the instructions on how to drain/refill ABC fluid. I am going to do my this weekend and hope everything will go smooth. I have received my order for the ABC filter and 5 Q of Pentosin CHF-11S.

COMEINPEACE

I have mentioned this once or twice before...
the petosin sitting on a shelf,in the can, has a shelf life of two yrs or so
can you imagine it being heated cooled repeatedly day after day?

seven_out

From the Pentosin product data sheet:
As an engineer, this suggests to me that its shelf life is unlimited. Further: (1) CHF 11S is not brake fluid, and (2) the temperatures ranges to which ABC fluid are subjected to are much smaller than that of brake fluid. According to Mercedes a 30-minute rodeo routine designed to heat the fluid will raise its temperature to just 80-degrees C.

COMEINPEACE

well there you have it then- no need to change it
the fact that it discolors means it is very stable,and does not break down... i guess

seven_out

It discolours while in a sealed can? Are you delirious?

Note that the fact that its shelf life is unlimited DOES NOT imply that its service life in an ABC application is unlimited. The fluid becomes contaminated with metal debris and other particulate matter which at some point warrants a flush and replacement with new fluid.

rune solem

I have an 2003 sl 55 where the oil hasn't been changed yet.

When I was at the mercedes dealership and asked if I should change it, they said NO.

They said that only if I got a problem with the suspension, should I do something about it.

So I'm waiting until a problem occurs before doing anything.

COMEINPEACE

Change your abc fluid
if your car was made in 2002/03 do the math
the pentosin is 12 to 13 years old
i am sure others will agree
very small and easily performed preventive maintenance

fxrs1955

I replaced my filter with the new style and flushed my system, replaced the rear accumulator. Well worth the time and effort.

funymuny

Newbie here. Doing all the reading I can about the ABC system. Torn about the flush. I have everything set to do my DIY flush. The only hesitation I have is would this somehow dislodge some particulates that might not otherwise come loose? Who knows...right? Mine is a 2004 with 67k miles. All seems to be working fine. Car sits level, no lights or warnings.

Love the car. These are a lot of car for the money (when you buy them used). The ABC system concerns me a little. What I'm learning is that parts seem to be becoming more available, lower cost, probably as the older cars are getting on the market and 'breaking'. I have seen reman Arnott struts for less than $500 each. Seems that if everything needed to be replaced...could be done for $5k - $6k and then it's good for another $100k miles or more??? I tend to not put many miles on my cars so that's essentially a lifetime.

I'm just trying to put an upper limit on my exposure to this item. There are some other things that can go, too. Understand. An ABC component seems the most likely to go...and most expensive.

Not really adding anything to this conversation...mostly commenting.

Thanks, Mark

seven_out

One of the objectives of a properly performed flush is to accomplish the very thing you are concerned about: dislodge and remove contaminants that would otherwise remain in the system. This will not happen if you use the ride height switch to help flush fluid from the system; instead, you need a $300 Chinese-cloned or other Star Diagnosis computer with its Rodeo and Pitch routines for actuating the suspension components.