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I am planning to flush the ABC system on my 2005 R230. I understand that I need to route the return line to a drain bucket while adding new Pentosin CHF11s to the reservoir. My problem is that I'm not clear on where the return line is attached to the reservoir. Is it the hose attached to the top of the filter in the bottom of the following photo? Ignore the green arrow, I borrowed this pic from another message thread and the arrow has no meaning here.
My Owner Manual shows Pentosin CFH11S as being correct for power steering but does not specify it for the ABC system. The ABC system calls for Mercedes hydraulic fluid. What is MB hydraulic fluid?
I also question whether I should do this at all. The car has 25000 miles so you wouldn't think that it was necessary yet but the fluid is brown and I have had the rear left sag on me when parked once or twice.
In your photo the return line is the hose that connects to the green cap. That cap is attached to the filter which you need to make sure to change. The ChF 11S is the correct fluid. The pump is a tandem pump that operates both the PS and ABC system.
In your photo the return line is the hose that connects to the green cap. That cap is attached to the filter which you need to make sure to change. The ChF 11S is the correct fluid. The pump is a tandem pump that operates both the PS and ABC system.
Thank you. I plan to buy two filters and ten quarts of fluid which is what seems to be recommended for a good flushing. I'll change the filter, flush the system and then change the filter again. It seems like a good plan to use a clean filter when flushing but do you guys think that it is overkill?
Also I wonder why the fluid is so brown after only 25,000 miles. Is that expected?
Change the filter when you flush the system. Change it again after you have put a couple of hundred miles on the car. The fluid will darken with age and mileage. If you have STAR, do a rodeo test before and after the flush and before you change the filter the second time. If you don't have STAR, raise and lower the car with the button on the console multiple times as you put mialage on the car.
Change the filter when you flush the system. Change it again after you have put a couple of hundred miles on the car. The fluid will darken with age and mileage. If you have STAR, do a rodeo test before and after the flush and before you change the filter the second time. If you don't have STAR, raise and lower the car with the button on the console multiple times as you put mialage on the car.
Are you saying to flush the system with the old filter and install new after flushing? Or do you mean to install the new filter and then flush? I don't like the idea of passing all of the new fluid through the dirty old filter.
Mike.
EDIT - NEVER MIND! It just occurred to me that the filter will be removed as I am flushing the system.
Last edited by mikefamig; Jul 15, 2019 at 06:54 PM.
Another newbie question just came to mind. Will I need to keep raising and lowering the suspension in order to flush the system or will the pump circulate fluid without doing this?
Another newbie question just came to mind. Will I need to keep raising and lowering the suspension in order to flush the system or will the pump circulate fluid without doing this?
My understanding is that most of the fluid is continuously circulating. It is the valve block that adjusts the height. I welcome any corrections from others.
Raising/lowering or doing a rodeo aids in clearing minute partials from the valve blocks.
My understanding is that most of the fluid is continuously circulating. It is the valve block that adjusts the height. I welcome any corrections from others.
Raising/lowering or doing a rodeo aids in clearing minute partials from the valve blocks.
That makes sense. I'll have to get a helper to push the button for me, No SDS here.
I've read that there is a 10 micron filter and a 3 micron filter available for the ABC system and that the 10 micron was stock in 2005. Is the finer filter recommended? A finer filter sounds like a good thing but could be more restrictive to flow. I've only found one part number - 0031846101 -for the filter. Is this 10 micron? 3 micron?
the info you have is current thinking. Mb doesn’t even recommend flushing .. but we all know it’s necessary
Do we? I'm not convinced that it's necessary but I do think that it's a good idea. New clean fluid is certainly better than dirty fluid that may have particulate in it that can interfere with a valve closing completely. It's good common sense. While my car is 14 years old it only has 25000 miles on it and would probably run a good while longer without the flush. I'm sure that there are many out there with a lot more miles that have run without failing. I'll do it becasue I like to keep my cars in good tune and well maintained..
You won't get all the fluid flushed without the proper procedure and an SDS. The struts are going to move up and down maybe an inch so although you will dilute the old fluid with new fluid it won't be a proper flush. If you don't have an SDS I'd recommend to use the bleeder screws at each corner to get more old fluid out rather than diluting it out by using the raise/lower method. Even with proper flush there can still be contaminants in the system and we have to use bleed screws. Early cars aren't so bad but a 2005 like yours has nitrile backup rings in the valve blocks so chances of contaminated fluid is higher
You won't get all the fluid flushed without the proper procedure and an SDS. The struts are going to move up and down maybe an inch so although you will dilute the old fluid with new fluid it won't be a proper flush. If you don't have an SDS I'd recommend to use the bleeder screws at each corner to get more old fluid out rather than diluting it out by using the raise/lower method. Even with proper flush there can still be contaminants in the system and we have to use bleed screws. Early cars aren't so bad but a 2005 like yours has nitrile backup rings in the valve blocks so chances of contaminated fluid is higher
Thanks for the info but I may still settle for the partial flush. Can you tell me where the drains are on the struts and how do I refill them after draining without running a lot of air through the pump?
Thanks for the info but I may still settle for the partial flush. Can you tell me where the drains are on the struts and how do I refill them after draining without running a lot of air through the pump?
Mike.
Follow the line from the strut, they are on the hard portion of it. What i will do is open the bleeder up with a hose on it going to a bottle or container to catch fluid. Do this with car jacked up as the pressure release will cause strut to lower. Then lower the car, top off reservoir and run the car, this will push all the fluid intended for that strut out through the bleeder. Depending on what I'm trying to accomplish you can use a drive on lift, close the bleeder allowing car to raise, then open it again to push all the fluid back out. Every now and then after rebuilding a valve block with nitrile rings there will be debris stuck in the line/strut after the valve block that is hard to get out and we use this route to do that but it can also be used when or a better flush then raise/lower. If its strictly for maintenance you shouldn't have any issues, just throwing it out there
Follow the line from the strut, they are on the hard portion of it. What i will do is open the bleeder up with a hose on it going to a bottle or container to catch fluid. Do this with car jacked up as the pressure release will cause strut to lower. Then lower the car, top off reservoir and run the car, this will push all the fluid intended for that strut out through the bleeder. Depending on what I'm trying to accomplish you can use a drive on lift, close the bleeder allowing car to raise, then open it again to push all the fluid back out. Every now and then after rebuilding a valve block with nitrile rings there will be debris stuck in the line/strut after the valve block that is hard to get out and we use this route to do that but it can also be used when or a better flush then raise/lower. If its strictly for maintenance you shouldn't have any issues, just throwing it out there
I really appreciate you pointing this out to me, I didn't know that the struts had bleeders. I think that I will do the the system flush via the reservoir return line and then run the car and and see if the fluid stays clean after putting some miles on it.
I did have the rear left sag on me when parked in the past but I can't remember how long it was parked. I've been driving the car every day or two now that the weather is nice and it has been fine. I will do the flush and if it sags again I will follow your procedure to flush the strut and hopefully clear any dirt that is causing the problem. If I still have a problem I'll consider rebuilding the valve block.
Mike.
Last edited by mikefamig; Jul 17, 2019 at 11:22 AM.
Follow the line from the strut, they are on the hard portion of it. What i will do is open the bleeder up with a hose on it going to a bottle or container to catch fluid. Do this with car jacked up as the pressure release will cause strut to lower. Then lower the car, top off reservoir and run the car, this will push all the fluid intended for that strut out through the bleeder. Depending on what I'm trying to accomplish you can use a drive on lift, close the bleeder allowing car to raise, then open it again to push all the fluid back out. Every now and then after rebuilding a valve block with nitrile rings there will be debris stuck in the line/strut after the valve block that is hard to get out and we use this route to do that but it can also be used when or a better flush then raise/lower. If its strictly for maintenance you shouldn't have any issues, just throwing it out there
I don't understand your procedure completely.
This is how I understand it
1 Start engine and raise ABC to it's highest setting
2 turn engine off
3 Jack the car up by the body
4 open the bleeder on one strut
5 lower the car/jack forcing fluid out of the bleeder into a bucket
6 close the bleeder
7 top off the reservoir
8 start engine and wait for ABC to raise the collapsed strut
Then repeat above for remaining three struts. Will this work? Will I get a good flush by doing one strut at a time?
1 Start engine and raise ABC to it's highest setting
2 turn engine off
3 Jack the car up by the body
4 open the bleeder on one strut
5 lower the car/jack forcing fluid out of the bleeder into a bucket
6 close the bleeder
7 top off the reservoir
8 start engine and wait for ABC to raise the collapsed strut
Then repeat above for remaining three struts. Will this work? Will I get a good flush by doing one strut at a time?
Mike.
Yes that is a good procedure, I add to it by leaving the bleeder open and running the car, pushing more fluid out of the bleeder
Yes that is a good procedure, I add to it by leaving the bleeder open and running the car, pushing more fluid out of the bleeder
I like that idea to flush the lines between the pump and strut but doesn't the fluid come out at very high pressure? The strut has to create enough pressure to lift the car.
I like that idea to flush the lines between the pump and strut but doesn't the fluid come out at very high pressure? The strut has to create enough pressure to lift the car.
Mike.
Yes it does. I crack it open quite a bit to allow bigger particles out and shove a tight fitting line on there. Once started it takes maybe 15-20 seconds to push a liter of fluid out. Here is the setup I use. You can watch through the wheel to see how much you have then lift it back up and close it off then follow the open/close steps a couple times. You don't have to do it this way I have just found it really helps getting some extra debris out.
I still haven't done the flush yet, the fluid and filters are still sitting on the floor of my garage. I hope to get it done before it gets too cold to work out there and another question has come to mind. If I open the bleeder on one of the struts and let the car drop to the bottom of the empty strut will the computer store an error code or need any attention or will the system just pump the strut back up when I start the engine? I do not have the SDS and if the car throws an error I have no way to reset it or adjust ride height or anything else like that.
I still haven't done the flush yet, the fluid and filters are still sitting on the floor of my garage. I hope to get it done before it gets too cold to work out there and another question has come to mind. If I open the bleeder on one of the struts and let the car drop to the bottom of the empty strut will the computer store an error code or need any attention or will the system just pump the strut back up when I start the engine? I do not have the SDS and if the car throws an error I have no way to reset it or adjust ride height or anything else like that.
Mike.
If you leave it running long enough. Even if it sets a critical level code it will go stored and not display after cycling key
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