Drain-and-fill methods and apparatus for automotive cooling systems

Abstract

A drain-and-fill machine is disclosed that can accommodate a cooling system having an inlet-side thermostat. The drain-and-fill machine includes a reservoir of fresh or recycled antifreeze/coolant and a reservoir to receive used antifreeze/coolant. The drain-and-fill machine introduces the fresh or recycled antifreeze/coolant into the cooling system of an automobile while simultaneously draining the used antifreeze/coolant into the used coolant reservoir. When the engine is cold, the engine's inlet side-thermostat will prevent new antifreeze/coolant from entering the cooling system, thereby making it possible to drain the used antifreeze/coolant from the cooling system, without simultaneously replenishing the cooling system with fresh or recycled antifreeze/coolant. The present drain-and-fill machine includes a thermostat disposed in the reservoir drain line having similar operating characteristics to the engine's inlet-side thermostat. The drain line thermostat will thus prevent the used antifreeze/coolant from being drained from the engine's cooling system when the engine's inlet-side thermostat is closed, until the coolant has reached a sufficient temperature to allow both the inlet-side and drain-line thermostats to open.