the switching valve 48 in the other connecting line 54 in the direction of the first line 40 if the pressure on the piston side 12 corresponds to the load pressure required movement begins immediately on the suspension cylinder 10 and the piston 22 with piston rod 24 begins to travel in the direction of the piston side 12 of the suspension cylinder 10 the pressure in the piston suspension reservoir 16 may be even lower than the pressure on the piston side 12 of the suspension cylinder 10 in particular the excess amount of fluid in movement for the purpose as indicated by the arrow from the piston side 12 is expelled in the direction of the side branch if the pressure on the piston side 12 is above the required load pressure m first fluid especially hydraulic fluid is drained from the piston suspension reservoir 16 by the 2 way 2 position piston locking switching valve 44 as indicated by the arrow in fig3 to the tank t until the load pressure m has been reached once the load pressure has been reached movement of the suspension cylinder 10 begins and the cylinder travels in the direction of the arrow when the suspension cylinder starts to travel hydraulic fluid is drawn from the associated rod suspension reservoir 18 on the ring or rod side 14 of the suspension cylinder 10 pressure equalization is then established between cylinder pressure on the rod side 14 and reservoir pressure for the rod suspension reservoir 18 at system pressure if the control system sensor device 11 and data interpretation unit 13 detects movement at the system suspension cylinder 10 the first.