When you put the cover back on, was the piston on the bottom of the smart mix knob? If it was, did you have the smart mix knob in the water only setting? Sometimes the flow indicator cap may be on too tight, loosen it while it is running until fluid starts to leak out, then tighten it until it starts spinning. On the bottom of the tanks, are the seals on the tank and not sitting the the hole. You may have pinched a line when you put the top cover back on. May still have junk in the lines somewhere, try running a mix of vineager and water (not on the carpet), that mix may clean it out.