Scientifically formulated to chemically repair minor head gasket leaks or small cracks allowing coolant to enter the combustion chamber, Rislone Block Seal Head Gasket Fix is a simple and cost effective solution to a difficult problem. Unlike other products which may require the coolant system to be drained, this product from Rislone can simply be added to the radiator regardless of the coolant currently being used. Once added to the cooling system, the heat from combustion is used as a catalyst to harden to repair fluid. Once hardened, the repair solution is generally stronger than the standard head-gasket material, creating a ‘ceramic-like’ seal perfect for preventing future leaks. This product is suitable for both petrol and diesel engines, with both cast iron and aluminium block constructions. So, the next time you have a minor internal coolant leak, try Rislone Block Seal Head Gasket Fix to keep your car off the hoist, and on the road.