Add contents to the cooling water. Turn the heating to maximum and let the engine run on idle for 10 - 30 minutes depending on the degree of contamination. Drain the coolant and flush the cooling system with water. Fill the cooling system according to the manufacturers instructions. The content is sufficient for 10 liters (2.6 gal.)of water, a minimum of 4 liters (1 gal.) is required for optimum product performance.