Abstract: Cleaning mechanism for a screen such as a radiator screen mounted adjacent an air-cooled radiator and air-circulating fan for a water-cooled engine to prevent debris from clogging the air passages of the radiator and including a frame supporting the screen as aforesaid, a motor driven shaft extending substantially centrally through the screen, transverse arms rotated by the shaft and having dislodging members in wiping relation to the air-inlet face of the screen, and baffle plates carried by the shaft for rotation relative to the air discharge face of the screen and in alignment with the arms and dislodging members to neutralize the suction effect of the air-circulating fan for the radiator and thereby permit debris dislodged by the members to fall by gravity from the screen.