Mercedes 560SEL hydraulic leveling system

First of all, I question their recommendation to replace the struts. In Mercedes with SLS, the struts are merely hydraulic rams that do not anything but raise or lower the car. If they aren't leaking externally, they are good. They very rarely fail. The shock absorption is performed by the accumulators which certainly do fail and there is no way to tell by looking at them. Blown accumulators caused a rock hard ride in the rear in my case. I would recommend taking the car to a independent Mercedes or European car shop. Do your research and find who is recommended in your city. I own a 560SEL too and my independent Mercedes shop was more than willing to replace the SLS system with 420SEL springs and Bilstein HD shocks. That said, I opted to have my SLS system repaired to keep the resale value and keep it original. Started by replacing the 2 blown accumulators (use genuine Mercedes only, was $196 each; the aftermarket ones don't last) and the rubber flex hoses to them. About 2 months after I had the accumulators and hoses to them replaced, the leveling valve failed, causing the rear to sag and the hydraulic pump started leaking externally. I replaced the leveling valve with a new Mercedes OE one ($400) and purchased a rebuilt pump with all new seals ($270). It is an expensive road to go down but I paid less than $2200 total to have nearly the whole system replaced. The SLS system should be reliable for about 10 years before I have to start worrying about the accumulators again. If you wish to tackle the job yourself, I highly recommend the SLS troubleshooting and repair manual written by Kent Bergsma. It is available on his website "wwww.mercedessource.com". He gives a tremendous amount of information on how to diagnose any SLS issue and how to replace various components. Unlike the factory manual, he will tell you the quirks of the system and everything you need to look out for. His manual describes the system in a W123 300TE wagon but it's the same setup on the W126 560SEL.

Years ago I purchased an '82 500SE and it has "regular springs" and shocks. I replaced them with Eibach performance springs and Bilstein shocks. Then when I got my first 560 I picked it up in Florida but as I drove home I hit my head on the roof of the car bouncing down the interstate. I went to change the shacks and found out they were $300 plus a shock but my parts supplier said he doubt if they were bad and suggest I'd the accumulators and sure enough ... $93 later the suspension was perfect That was my first experience with SLS