How to Change a Serpentine Belt on a F250 Fordby Thomas WestUpdated November 07, 2017
The 3/4-ton F250 Ford pickup truck is the next step up from the half-ton F150. Utilizing a heavier frame, suspension and drive train, the F250 can handle larger payloads than the half-ton version. The F250’s serpentine belt is located on the front of the engine and drives all of the accessories, such as the power steering pump, alternator, air conditioning compressor and fan. Your maintenance regimen should include checking your serpentine belt for cracks or other damage and replacing it as needed.
Open the hood. Locate the serpentine belt routing sticker affixed to the metal radiator support cross member. Make a sketch of the routing of your serpentine belt if your truck does not have a routing sticker. Make sure to note whether the ribbed side of the belt goes over the engine pulleys or the smooth side of the belt, as this will make the installation of the new belt quicker.
Locate the belt tensioner, which is mounted on the passenger side of the front of the engine. Insert the end of a 1/2-drive ratchet wrench into the square hole on the belt tensioner.
Rotate the ratchet wrench counterclockwise slightly and hold it there, which releases the belt tension. Slide the belt off of the idler pulley, which is at the top of the engine in the center. Release the belt tension by letting up on the ratchet wrench handle slowly, as the tensioner spring is under a lot of pressure. Remove the ratchet wrench from the engine compartment.
Slide the serpentine belt off of the remaining engine pulleys and place it aside. Compare the old and new belts to make sure they are the same thickness, width and diameter.
Following the belt routing instructions on your truck’s sticker or from your sketch, place the belt over all of the pulleys except the idler pulley at the top center of the engine. Place the 1/2-inch ratchet wrench back into the square hole in the belt tensioner and rotate it counterclockwise. Hold the ratchet handle while sliding the serpentine belt over the idler pulley. Release ratchet handle slowly as the tensioner tightens the belt onto the pulleys. Remove the ratchet from the engine compartment.
Make sure the belt is riding in the center of all of the pulleys. Release the belt tension and reposition the belt if necessary. Start the engine and observe the belt operation.