To check to see if it is this system just look and see if the car has any coil springs for the suspension, sorry I should of asked that before. If it doesn't then this is the system it has for the suspension. To check leveling valves for adjustment disconnect the rods from the valves and raise (fill) the car to it full up postion then lower (empty) the system by moving the control rod untill the car settles down. This is noraml ride height for the car. On the valve there is a 4mm hole and the control rod has the same 4mm hole, they should line up or real close to it. If it is out of adjustment readjust it and see if it fixes the problem. As for checking the pressure regulator it is a bit more involved and requires high pressure guages to check it but like someone said this is on the 124 CD-Rom. Good luck!