An electronic rack liquid cooling system includes a rack manifold having a rack liquid supply line or channel and a rack liquid return line or channel. The liquid supply line is to receive first cooling liquid from a cooling liquid source and the liquid return line is to return first warmer liquid carrying the exchanged heat back to the cooling liquid source. The electronic rack further includes an array of server blades arranged in a stack therein. Each server blade includes one or more liquid cold plates associated with one or more information technology (IT) components. The electronic rack further includes a set of one or more liquid distribution units (LDUs) coupled between the rack liquid supply and return lines and the server blades. Each LDU includes an LDU container, a liquid supply port, a liquid return port, one or more pairs of supply sub-ports and return sub-ports, and a heat exchange channel or tube.