CL-Class (W215) 2000-2006: CL 500, CL 600

ABC again: still sag after valve repair

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Old 01-08-2015, 06:35 PM
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W215 CL500 2000
Unhappy ABC again: still sag after valve repair

My CL was sag on the front left after engine off for about 1-2 hours. Tried to remove and clean the valve, and bleed the air with up and down button for about 15 times.
After that, the car can keep its height, but its only for 1-2 days and it sag again on the front left. And on the same time the fluid was leaked from the top of reservoir, and checked that the fluid was under the minimum dipstick after the oil pushed out.
Should I run the rodeo? or should I remove and clean the rear valve block as well?

Thanks in advance
Old 01-08-2015, 08:37 PM
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Mercedes
I think I've seen other people say that fluid spitting out means the air cells /accumulators are bad
Old 01-09-2015, 04:55 AM
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W215 CL500 2000
Originally Posted by tusabes
I think I've seen other people say that fluid spitting out means the air cells /accumulators are bad
Thank you for your reply. I have checked the accumulator diaphragm and it seem okay, and I don't have humming sound or ABC warning when driving over a bump.
Old 01-09-2015, 07:36 PM
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Originally Posted by imantr
Thank you for your reply. I have checked the accumulator diaphragm and it seem okay, and I don't have humming sound or ABC warning when driving over a bump.
I just run the rodeo, the idle pressure is 189 bar, while during rodeo is 110-112, and I hear hiss sound during rodeo, is it normal?
Old 01-10-2015, 06:16 PM
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W215 CL500 2000
Originally Posted by imantr
I just run the rodeo, the idle pressure is 189 bar, while during rodeo is 110-112, and I hear hiss sound during rodeo, is it normal?
I just realized the car now sag on the left side (front and rear) for about 1cm. Any advice?
Old 01-13-2015, 01:21 PM
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2006 S600
Originally Posted by imantr
I just run the rodeo, the idle pressure is 189 bar, while during rodeo is 110-112, and I hear hiss sound during rodeo, is it normal?
Other people may have more experience of this than me, but I wouldn't worry about the pressure drop too much, as rodeo is not normal operation for ABC, its an abitrary testing and flushing exercise for the hydraulics.

The struts are normally actuated by quickly discharging fluid that is stored at operating pressure in the accumulators. The accumulators are re-charged to normal pressure in slow time, when the pump has time. Strut actuation only has low duty cycle, so the pump's output is stored like compressed air.

If they didn't do it this way, the pump would have to be much bigger and power hungry to be able to actuate the struts fast enough to meet the dynamic demands of the system. However, during rodeo, the pump is having to work continuously - it never gets any off-duty time to recharge the accumulators. The high pressure is being used as fast as its being pumped, so it isn't stored.

I guess its like the output of the pump is fed directly to each strut in turn, and forces them up at the speed of the pump. Therefore the ABC pressure is no longer the pressure that the pump is capable of, but the pressure it needs to lift each corner in turn. That's the way I read it.

Nick

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