How to Change the Fuel Filters on a F350 Super Duty

The F350 is a one-ton truck model offered by the Ford Motor Company. The Super Duty nameplate was first used on heavy duty F250 three-quarter ton and heavier trucks starting with the 1999 model year. Many F350 Super Duty trucks came from the factory with diesel engines. Fuel flowing from the tank to the diesel engine was filtered two times on these trucks -- first through the Horizontal Fuel Conditioner Module, located under the truck, and then through the engine-mounted filter.

Things You'll Need

  • Drain pan
  • Socket set
  • Ratchet wrench
  • Clean cloth
  • HFCM fuel filter
  • Engine-mounted fuel filter

HFCM Filter

  • Turn off the ignition key and apply the parking brake. Slide under the truck and locate the fuel filter housing mounted on the inner side of the driver's frame rail, near the transmission case. Place a drain pan under the housing.

  • Turn the drain lever on the housing outward and away from the frame, and allow the housing to fully drain of fuel. Rotate the drain lever inwards, towards the frame, until it latches. Remove the drain pan from under the truck.

  • Place a socket over the hex fitting on the filter housing cover and twist it in a counterclockwise direction, using a ratchet wrench, to remove the cover from the housing.

  • Pull the fuel filter element straight off the inside of the filter housing cover and discard it. Wipe the filter mating surface in the housing with a clean cloth. Roll the O-ring gasket from the groove in the cover and discard it. Stretch a new gasket -- included with a replacement fuel filter -- over the cover and into the groove.

  • Push a new filter element into the underside of the filter cover until it is fully seated. Thread the cover back onto the filter housing. Tighten the cap in a clockwise direction, until it makes contact with the housing.

Engine-Mounted Filter

  • Open the hood and locate the fuel filter housing on the top-center of the engine. Place a socket over the hex fitting on the filter housing cover and twist it in a counterclockwise direction, using a ratchet wrench, to remove the cover from the housing.

  • Pull the fuel filter element straight off the inside of the filter housing cover and discard it. Wipe the filter mating surface in the housing with a clean cloth. Roll the O-ring gasket from the groove in the cover and discard it. Stretch a new gasket -- included with a replacement fuel filter -- over the cover and into the groove.

  • Push a new filter element into the underside of the filter cover until it is fully seated. Thread the cover back onto the filter housing slowly, allowing the fuel contained in the housing to soak into the element as you go.

  • Tighten the cap in a clockwise direction, until it makes contact with the housing.

  • Turn the ignition key on, without starting the engine. Wait 30 seconds, then turn the key off. Do this five more times to purge all remaining air from the fuel system. Start the engine and allow it to run until it idles smoothly.