Abstract: An apparatus that cleans printed wiring assemblies. A plurality of assemblies are positioned in a rack on their respective edges so that each of them is maintained in a substantially vertical plane. A spray header member mounted for reciprocation between an uppermost and a lowermost position has a plurality of horizontally disposed support members that are positioned in staggered relation to the assemblies to be cleaned so that when the header member travels downwardly, the support members enter into the spaces between the rows of assemblies. A plurality of nozzles are formed on the support members, and direct a fan-shaped spray onto the assemblies both during the downward travel time of the spray header member and its upward travel time. The spray impinges the assemblies at a forty five degree angle. Depending upon the cycle being undergone, the nozzles discharge a caustic cleaning solution, domestic potable water, or a dionized water rinsing solution.