Flexbilt offers a great proudct that Removes deposits in cooling systems of all water cooled engines. It removes scale, grease, sludge and other deposits to allow restored performance and proper cooling performance.
Liqui Moly Radiator Cleaner - 300ml
Suitable for all coolant and heating systems. Does not contain aggressive acids or alkalis and is acid neutralising. Contents (300 mL) is sufficient for 4–10 Liters (1 gal. to 2.6 gal.) coolant water.