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SLS Experts, Please

2108 Views 8 Replies 6 Participants Last post by  Real1shepherd
Hey folks,

So Yesterday I replaced the SLS accumulators on the S124, ride is MUCH better now.

I lost about 1L of fluid while changing the spheres (what was in them & their lines) however after the change when i started the car up to top up the reservoir, the level hadn't moved. This is with two guys sitting on the back, engine at 2k rpm etc... nothing. Took it for a drive around the block, still no movement. Ride height is normal, not sagging or too high.

I did the job at my parents place then drove it back to my house 15km away. Started it up this morning, still no decreased level in the reservoir.

So today I took the reservoir out and it was filled with a dark brown fluid with gunk at the bottom, cleaned that out and topped up with Penrite MB15 (MB343.0/ZHM equiv.) and ran the car with the return line disconnected.

It pumped out about 500ml's of the brown fluid and then ran clear (the colour of the Penrite) however it hasn't appeared to have pumped anything out from the rest of the system.

Is there a way I can completely flush the system of the old fluid? I've looked at quite a few articles on various forums and it's a bit confusing. Does the rear bleed valve do the whole system or just purge the accumulators?

Just wondering if there's a sure fire way to flush the whole thing out.

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You've done about as complete a job as possible. Your method of changing the fluid worked very well for all the fluid between reservoir, pump and the control valve in the rear suspension. All the fluid in the accumulators, struts, and the lines between them can only be changed by removing and draining all those components, which is not very realistic.

I disagree with the contention that the system is self bleeding for the reason in my first paragraph. I prefer to bleed any air in the system by loosening the hose connection at the top of each rear strut. Let all the foamy fluid out until nothing by pure fluid is draining, then tighten back up and check your reservoir after running the engine for a few minutes to re-pressurize the system.

The bleed valve on the control valve is really only useful for relieving the system pressure prior to working on the system, and for draining some of the fluid out. This bleed valve will not get all the fluid out of the struts and accumulators, but you can get a good bit out.
I think if you manually raise and lower the car with the SLS valve lever after disconnecting the link, you can get a good fluid flush. This process fills and empties the struts and gets fluid moving through the system.
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