I am pretty confident my lack of SLS is due to my tandem pump not putting adequate pressure to raise rear.
I am planning to get a used junkyard Vickers 124-460-15-80 Tandem pump and rebuild it using the Febi seal kit since the kit is only $18.
Anybody done this?
I found this youtube video and it doesn't seem incredibly difficult...
Rebuilding the Self-Leveling System Pump in a W126 Mercedes - YouTube