Flushing the radiator on your 1998 Ford Ranger needs to be done at least once a year to keep the radiator clean of debris and sediment. This procedure also helps to ensure the radiator does not get clogged and is capable of sending fresh coolant into the engine to prevent the engine from overheating. Purchasing pre-mixed coolant will ensure the required 50 percent anti-freeze and water mix for your Ranger's coolant system.
Park the truck on a flat surface and set the parking brake. Open the hood to access the engine compartment.
Place a drain pan under the radiator. Locate the drain valve at the bottom passenger's side of the radiator. Open the valve by turning it counterclockwise with a crescent wrench. Allow the coolant to drain into the drain pan.
Fill the radiator with water by unscrewing the pressure cap on top of the radiator counterclockwise and pouring water into the opening.
Start the truck and allow it to run. Observe the water coming out of the bottom of the radiator. Be sure to change the drain pan so none of the old coolant leaks onto the ground. When the water pouring out of the radiator is clear, turn the truck off and allow the remaining fluid to drain out of the radiator.
Tighten the drain valve with the crescent wrench. Pull the drain pan away from the radiator.
Fill the radiator with coolant. When the radiator is full, start the truck and allow it to idle until it is warm. Pour coolant into the radiator until it is full then tighten the radiator cap.
Close the hood. Turn off the truck.
