Pneumatic spring assembly for a commercial vehicle

The air-suspension system (1) has a lift-lower valve assembly (3) having lifting-lowering valves (7a,7b), and a level control valve assembly (4) comprising electro-pneumatic servo valves (38a,38b). The lifting-lowering valves and electro-pneumatic servo valves are arranged in parallel line branches and are operated based on primary control pressure value and secondary control pressure value respectively. The air-suspension bags (5a,5b) are operated based on the position of ventilation valve (23) and or shut-off valves (25a,25b) provided in level control valve assembly.