Help ! I killed my vacuum!!!!?

I put some 7 dust on the carpet 4 fleas and my vacuum started running kind of loud after I vacuumed it up . So I took it apart and cleaned it out and put it back together ( this was hard since I could not remember how it went back ) now it sounds fine but no suction. It is a MAYTAG canister (bagged) . What could it be? I suspect it has something to do with the vacuum seal not being tight.. but I cannot find a loose connection.