OK, so if I pull the returm hose, attach a drain hoseline, then run the engine, that will drain all or most of the fluid?
I'm not familiar with the method, just making sure it's OK to run it dry for a couple of seconds. Is it self-bleeding?

Or did you mean use the siphon suction pomp on the return hose after sucking out the reservoir? (manually)

Thanks

 

yes, that way.

remove the reservoir cap with filter together. you need to get all the new fluid ready...un capped and beside you because it will be a very quick pace. always watch that the fluid on the reservoir don't get low.

 

As a follow up,
I'm out at the other house and saw that the CL 600 was way down on its RF corner. So, the oil change and top up or the ABC didn't help. I have made an appointment with the MB dealer service to examine/replace the offending valve.

Note: it jumps right up after pressing the height-adjust button. Are these 2 systems: Ride Height and ABC - interconnected?

 

it belongs to ABC.

the ADS is controlled by ESP. (hard and soft ride).

 

More follow up...

My dealership performed the recall service for hydraulic line; informing me that that could be the problem. No charge but it didn't fix the problem.
Fter 2 weeks sitting, it's drooped down again. I'll have to bring it in again.

 

the hydraulic line is an oil leak problem. it's the one going around on the top of bell housing. that's not the problem of your car because you never complain of oil leak but suspension drop.

 

I have a '02 CL500 and the front also drops (evenly) after sitting 2 weeks or so. (It does rise to normal ride height after start up). I've had it in to MB twice and the first time they replaced a valve which they said had an internal leak. They also flushed the system, both procedures in accordance with a service bulletin. After they did the work, I let it sit again and, not surprisingly, the front droped again I took it back last week but they could find nothing wrong, including finding no fault codes. Of real interest though is that the MB shop foreman told me that he had seen brand new, yet to be titled cars on their lot that had also dropped.
Based on this, I'm fairly convinced that this is not a problem. Anyway, I'm on record for this problem with MB. I go from factory warranty to Starmark Warranty in about a month which they tell me would cover the ABC system.
I hope this is not too late for someone to benefit from this.