A locomotive engine having an engine cooling system, a compressor for compressing engine intake air, and an aftercooler for cooling the compressed intake air prior to introduction into an intake manifold of the engine. The locomotive also has a dynamic brake system that includes a dynamic brake grid and one or more cooling fans. The engine cooling system includes an engine cooling circuit having coolant passages internally disposed in the engine, and a radiator and radiator fans configured to receive coolant exiting the engine and return cooled coolant to the engine. An enhanced aftercooler cooling circuit is disposed in fluid communication with the engine cooling circuit and includes a heat exchanger arranged to receive coolant exiting the engine coolant passages, cool the coolant passing therethrough, and return cooled coolant to the aftercooler. The heat exchanger is advantageously positioned in a manner whereby the dynamic brake grid cooling fan is operatively associated with both the dynamic brake grid and the heat exchanger.