Abstract: A crankcase ventilation system for a vehicle includes an arrangement of flow conduits and control valves which cooperate with a two-chamber accumulator and with various vehicle components to route crankcase gases to the intake manifold. The primary vehicle components include a compressor, an aftercooler positioned downstream from the compressor, and an engine having an intake manifold and a crankcase. One chamber of the accumulator is coupled by one conduit to the inlet side of the compressor and by a second conduit to the outlet side of the compressor. These two conduits are controlled by a dual valve arrangement. The other chamber of the accumulator is connected by one conduit to the crankcase and by a separate conduit to the intake manifold. Each conduit includes a control valve. The system operates on pressure differences existing between these various components. The cycle begins by opening the conduit which is connected to the inlet side of the compressor.