Penrite Radiator Flush Cleaner 20 Litre DrumPenrite Radiator Flush Cleaner 20 Litre Drum Radiator Flush is a fast acting (7 Minute), alkaline cooling system cleaner designed to remove rust, scale and other deposits from automotive cooling systems that could block or foul circulation of coolant though the radiator or engine. APPLICATION Radiator Flush is recommended to clean out the cooling system of all types of passenger cars, 4WD's, light & heavy duty commercial vehicles, motorcycles,