Compatibility of External Life Coolant Systems with Plastic Components 970075

The ethylene glycols which the OEM's are using today in the engine cooling systems have been under review by the federal government as proposed restricted substances, meaning that in the near future coolants must be screened by the OEM and reformulated or redesigned. In order to minimize handling of the coolant systems, ethylene glycol based systems containing organic acids as the primary corrosion inhibitors (vs. the conventional inorganic inhibitors widely utilized today) are being introduced to the market. The primary advantage of these systems is non-depletion of the inhibitors, allowing extended service intervals, where the coolant is changed between 100,000 - 200,000 miles versus 30,000 - 50,000 miles with the current systems utilizing inorganic inhibitors. This benefits the consumer and the environment.

Plastic components are widely used in coolant systems where radiator end tanks, water pump impellers, inlets, outlets, and thermostat housings can be polymeric. A study was conducted in which a number of engineering plastics were exposed to long life coolants at elevated temperatures and pressures to determine the effect of the coolant. The intent of the study was to provide insight into plastics which can withstand the hot acid environment of extended life coolants during usage. Several extended life coolant systems were investigated, including one containing 100% remanufactured glycol, furthering a more environmental friendly system.