1996 Ford F250 Owner's Manual - Page 328

Engine coolant drain and flush To drain your vehicle's engine coolant: 1. Turn off the engine and let it cool. Fully depressurize the engine cooling system by covering the radiator cap with a thick cloth and turning it slowly counterclockwise to the first stop. Step back while the pressure releases. Remove the cap. Attach a small hose to the drain tube at the bottom of the radiator. Let the engine coolant drain into a suitable container. Disconnect the lower radiator hose at the radiator connector and drain any remaining engine coolant into a container. Reconnect the lower radiator hose and close the radiator drain cock. 2. 3. 4. 5. Proper procedures for flushing the cooling system can be found in the Truck Service Manual. Engine coolant refill procedure After you have drained the engine cooling system: 1. Fill the radiator with a 50/50 mixture of the specified engine coolant concentrate and water. Allow several minutes for trapped air to escape (bubble out) and for engine coolant to flow through the radiator. Replace the radiator cap to its fully installed position, then back off to the first stop. This will prevent high pressure from building up in the cooling system during this part of the fill procedure. 2. 329