Does anyone know if a 2001 S55 AMG Hydraulic Suspension Valve is threaded within the valve unit or if it has a seal?

there are several valves, solenoids and sensors. exactly what one are you talking about. give the location please.

you do realize that this system has major amounts of pressure in it. if you don't know the system it is not recommended you touch it. i hate to say it but don't even open up the system without a scan tool to perform the bleed procedure.