Abstract: A leak tolerant liquid cooling system for electrical components comprises a cooling circuit which contains a pump and conduits that circulate a liquid coolant past the electrical components and through the bottom chamber of a purge tank. This purge tank also has a top chamber which is connected to the bottom chamber through a passageway; and, the bottom chamber is sized such that the liquid coolant passes through it with a velocity which is low enough to let any air bubbles in the coolant rise and move by buoyancy through the passageway into the top chamber. Air is purged from the top chamber through a valved output port by forcing liquid coolant into the top chamber through a valved input port. To complete this purge quickly, the passageway between the purge tank chambers is configured in a way which hinders the flow of coolant from the top chamber to the bottom chamber while the coolant is being forced into the top chamber.