Can Bar’s Leaks HEAD GASKET & COOLING SEALANT be installed in existing antifreeze?
Yes, it is compatible with ALL types and brands of antifreeze including conventional green or blue (Silicate-Based) and extended life red/orange or yellow (OAT/HOAT) coolant. It also works in systems containing only water. Cooling systems that are dirty or partially clogged a flush is recommended before use.