The Space Station Freedom internal thermal control system (ITCS) consists of multiple, closed water loops which collect heat from cabin atmosphere, avionics equipment, life support subsystems, and direct electronic loads, and transport it to interface heat exchangers for rejection to an external central thermal bus. One subsystem of the ITCS is the pump package assembly, which provides coolant circulation, water filtration, gas separation, and flow monitoring. Major components include a pump, motor, motor controller, filter, gas trap, accumulator, and sensors.The pump package assembly was originally designed to meet a coolant flow rate requirement of 1230 lb/hr. During 1992, the flow rate requirement was increased to 3000 lb/hr, prompting redesign of the pump. This paper describes the design of the pump package assembly and presents results of development testing on pumps of both sizes.