The invention relates to a fluid system (50) for cleaning machine (1), which comprises a floor treating brush and/or disc (7) rotatably driven by a motor (4) and exhibiting surrounding ring-shaped rim (8) and conduit for washing liquid and vacuum suction duct for the supply (11) of washing liquid (12) and suction (13) of washing liquid (14), respectively. A disc-shaped bottom part (25) provided with substantially radially extending vacuum suction ducts (24) is located above said rotatable brush and/or disc (7). A bottom cover (51) is connected to said bottom part (25), and nozzles (27) are connected to said vacuum ducts (24) along the periphery of said bottom part (25) and bottom cover (51) in order to suck up dirty washing liquid (14). Said bottom cover (51) and said bottom part (25) can be released from one another in order to reach said substantially radial vacuum suction ducts (24) located between them (25, 51).