Valvoline Radiator Stop Leak is a low-cost method of sealing all types of cooling system seepage and leaks.

Radiator Stop Leak features a unique combination of high-molecular natural components and advanced leak-sealing components dispersed in a corrosion inhibited liquid.

Designed for use in all types of cooling systems, except for heavy-duty diesel cooling systems.

>> Stops radiator leakage in seconds
>> Contains only very small particles that will not clog even the smallest engine passages
>> Compatible with water and all conventional coolants/antifreezes
>> Contains no metals