PURPOSE: To make it possible to increase the vehicle level upon resting of the engine, by providing such an arrangement that the supply of pressure oil is made by a pump to increase the vehicle level upon running of the engine while it is fed from accumulated oil in an accumulator is utilized upon resting of the engine.

CONSTITUTION: Upon increase of the vehicle level during operation of a pump 26 a shut-off valve 42 is closed and a shut-off valve 65 is opened by a vehicle level adjusting switch 72 and vehicle level sensors 68, 69 while selector valves 43 through 45 are set to their second position. Further hydraulic pressure from the pump 26 is fed to actuators 2 through 5 so that the increase of the vehicle level is made by hydraulic pressure from the pump with no accumulated pressure in an accumulator 38 being dissipated. Upon resting of the pump 26 the shut-off valve 65 is opened, and the selector valves 43 through 45 are changed over to supply accumulated pressure in the accumulator 38 for increasing the vehicle level. With this arrangement, variation of the adjusting speed of the vehicle level is restrained so that the vehicle level may be increased upon resting of the engine.