Things You'll Need
Serpentine belt tool
If the serpentine belt on your Ford E350 van should break while driving, you'll end up on the side of the road until a tow truck arrives. To make matters worse, the belt can damage the coolant hoses, electrical wiring and other components when it breaks. This is why Ford Motor Company recommends inspecting the belt regularly and replacing it at the first sign of frayed edges, excessive cracking or rib loss. If you have basic auto-repair skills, you can replace the Ford E350 serpentine belt in less than one hour.
Open the hood and remove the air filter intake duct using the socket set. Find the E350's belt routing diagram and familiarize yourself with it.
Move the E350's serpentine belt tensioner off the belt with the serpentine belt tool. Slip the belt off the tensioner pulley by hand. Move the tensioner back into place.
Pull the belt off the E350's engine accessory pulleys and crankshaft pulley by hand. Lift the belt out of the engine bay.
Stretch the E350's old and new belts out side by side to compare their lengths. The new belt should be roughly 1/2 an inch to 1 inch shorter than the old belt. This discrepancy is due to stretching that occurs during the belt's lifetime.
Loop the belt around the bottom of the E350's crankshaft pulley by hand. Follow the belt routing diagram precisely to route the belt around each of the engine accessory pulleys.
Move the tensioner out of the belt path once more. Slip the E350's new belt over the tensioner pulley by hand. Hold the belt to the pulley and slowly move the tensioner back into place.
Remove the serpentine belt tool by hand. Close the E350's hood.