Abstract: A filter dust ejector with a built-in check valve as part of the exhaust system of an internal combustion engine, the ejector consisting of an ejector housing with a suction connector for an air hose leading to the air intake filter, and inlet and outlet pipes forming an annular suction gap in a venturi-type exhaust flow profile, thereby creating a negative pressure in the ejector housing. The inner extremity of the suction connector is a valve seat for a pivotably supported flapper serving as a check valve which is closed, when a pressure condition in the ejector housing tends to create a reverse flow of exhaust gas through the suction connector to the air intake filter.