S430 Air Suspension Fix Is your Mercedes sagging overnight or riding unevenly? John digs into a full air suspension repair on this S430. This S430 came in with classic air suspension issues, and John is breaking it down from the pump to the struts. The real culprit turned out to be a failing valve block that needed a precise replacement. Air suspension systems on the 220 chassis require careful diagnostics to prevent more costly failures later. If your ride height changes or you hear the pump ru