1997 Ford F350 Owner Guide 1st Printing - Page 275

5. Stand away from the radiator opening. Hot steam may blow out or hot engine coolant may even splash out. Freezing Protection The factory-installed solution of Ford Premium Cooling System Fluid and water will protect your vehicle to ȕ35˚F (ȕ37˚C). Check the freeze protection rating of the engine coolant at least once a year, just before winter. Add engine coolant only to the coolant reservoir. If the coolant level is low, add to the reservoir a 50/50 mixture of water and the type of engine coolant that Ford specifies. You may add water by itself only in an emergency, but you should replace it with a 50/50 mixture as soon as possible. Check the engine coolant again the next few times you drive your vehicle. Ford Premium Cooling System Fluid is an optimized formula that will protect all metals and rubber elastomers used in Ford engines for four years or 50,000 miles (80,000 km). It is not necessary and not recommended to use supplemental coolant additives in your gasoline powered vehicle. These additives may harm your engine cooling system. Follow the recommended service interval for changing your engine coolant. NOTE: When you change or add engine coolant, it is important to maintain your engine coolant concentration between 40% (-11˚F [-24˚C]) and 60% (-62˚F [-52˚C]), depending on your local climate conditions. Below 40% you will lose freeze protection and above 60% your engine may overheat on a warm day. 276