A. Consider the facts. Seven out of ten cooling systems have rust and scale in less than five years. Greater than 60 percent of water pump failures relate to seal failure due to acidic fluids in the cooling system. Fifty percent of engine failures can be attributed to cooling system failure. Even 1/16-inch deposits on cast iron reduce heat dissipation by 40 percent. Low coolant level can create room for steam and destroy the radiator from the inside out. The radiator and heater hoses generally fail from the inside out due to electrolysis particularly after the fourth year of service. As antifreeze degrades, it becomes acidic. You should have your coolant system checked every year and antifreeze/coolant replaced at least every two or three years.