Abstract: A paint spray-gun cleaner includes a tank having an upper chamber for receiving the paint spray-gun to be cleaned, and a lower chamber for containing a cleaning solvent. The solvent is forced to flow from the lower chamber to the nozzles in the upper chamber by a solvent pumping unit. Compressed air is intermittently supplied to the solvent pumping unit so as to force the solvent out of the solvent pumping unit. When a cover is placed on the top of the tank to seal the upper chamber, the poppet valve of a switch is opened, thereby permitting compressed air to pass through the switch to the solvent pumping unit. When the cover is opened, the switch is closed and the flow of compressed air into the solvent pumping unit is thus stopped.