For large cooling system leaks, little time and less money, Bar’s Leaks offers the Bar’s Leaks Liquid Copper (No. 1109). Liquid Copper repairs heater core leaks and cracked cylinder heads, fixes blown head gaskets, and seals freeze plug and block leaks. Liquid Copper uses an advanced antifreeze-compatible sodium silicate liquid glass formula so no draining of the cooling system is required. It works with all types and brands of antifreeze, including conventional green or blue (silicate-based) and extended life (red/orange) or yellow (OAT/HOAT).