Cooling System Home / Car Maintenance / Cooling System / Wynn's Radiator Stop Leak 325ml. 55864 Wynn's Radiator Stop Leak 325ml. 55864 Wynn's Radiator Stop Leak 325ml. 55864 £4.99 Stock Status: In Stock Information Wynn's Radiator Stop Leak 325ml Wynn's Radiator Stop Leak is a sealing product to stop small leaks in the cooling system, with anti-corrosive properties. Stops and prevents leakages in the radiator, cooling and heating system. Stops head gasket leaks. Will not harm rubber hoses, gaskets or other system components. Is compatible with all antifreezes and coolants, also with OAT coolants (Organic Acid Technology). Is formulated to avoid clogging of radiator waterways and temperature sensors. Enhanced protection against rust and corrosion. Recommended for all "water" cooled systems of petrol, LPG and diesel engines when minor leaks are noted. Can also be used as preventive agent. Contents treat a cooling system from 5 to 12 litres.