KleenTec Antifreeze Recycling Additive PR26PR26 Additive controls cylinder liner cavitation at the same time that it is protecting the cooling system from deposits corrosion. Preparol 26 is designed to reduce inhibitor over concentration and silica gel formulation, all the while protecting any standard coolant system components. PR 26 additive was specially formulated to return the recycled coolant byproduct back to it's original state (after being mixed with water). It infuses corrosion