Abstract: In an injection molding system a cooling manifold system includes a first manifold disposed adjacent to a second manifold. Supply valves are arranged to selectively pass a coolant from the first manifold respectively to each of a plurality of mold cooling circuits and a plurality of return valves are arranged to selectively pass the coolant from the plurality of mold cooling circuits to the second manifold when one or more of a plurality of return valves is in an open position. Valve pairs associated with a common mold cooling circuit are mechanically linked so that operation of a supply valve and return valve can be concurrently performed from one side of the manifold system without interference from a plurality of hoses attached to the supply and return valves.