Irontite ThoroFlush (468-9110-16) Industrial Strength concentrated radiator, engine coolant system and fuel tank cleaner Loosens and removes rust, scale, grease, oil and sludge Cleans Auto, HD Truck and Equipment Cooling Systems Safe for use on Cast Iron, Aluminum or Plastic Opens and cleans out plugged heater cores. Clears out gelled Dex-Cool with a simple ush Diesel Oil cooler failure, cleans cooling system in a single ush Safe for use on cast iron, aluminum, brass and plastic For improved coolant ow and temperature control, always ush with Thoro-Flush for the best possible results Thoro-Flush is a concentrated powder and the most powerfulush available