Brush not turning and no suctions !

If the cogs on the belt and brush roll are ok, then probably the cogs on the pulley are worn off, or the pump isn't turning, is the flat belt ok? If all of this is ok, then replace the pump, part # 2107181If no suction, is the black oblong gasket on the top of the clear window. It seals the gap between the tank and the window, no suction if it is gone. Also should be a red plastic screen on the edge of the tank lid, it may be clogged.