6.4 Power Stroke Fuel Filter Service

Ford recommends changing the fuel filters on all 6.4L Power Stroke equipped trucks at 20,000 mile/24 month intervals (whichever comes first) under normal operating conditions and every 10,000 miles/400 engine hours (whichever comes first) under severe operating conditions. Vehicles that tow frequently, idle extensively (more than 10 minutes within a 60 minute period), experience frequent stop-and-go traffic conditions, or that operate on biodiesel fuels fall under the severe service category. We strongly recommend draining the fuel-water separator at oil change intervals, or more frequently if water contamination is an issue in your location.

The 6.4L Power Stroke features a dual fuel filter system that is extremely similar to that found on the 6.0L Power Stroke. The primary fuel filter is contained inside an assembly referred to as the Horizontal Fuel Conditioning Module, or simply HFCM. In addition to housing the fuel filter, this unit also contains the fuel-water-separator system. It is located on the inside frame rail on the driver side of the chassis between the fuel tank and engine. The secondary fuel filter is mounted on the top of the engine to the right (standing at the radiator and looking at the engine) of the oil filter housing.

When servicing the fuel system, both fuel filters should be replaced and the fuel-water-separator must be drained. The fuel filters are sold as a set and the Ford/Motorcraft part includes new o-ring seals for both filter housings. Failure to change the fuel filters routinely may result in contamination of the fuel system and ultimately severe damage to relatively expensive injection related components.

6.4 Power Stroke Fuel Filter Part Numbers

[1] - Includes engine and chassis mounted fuel filters, all required gaskets
[2] - Reusable; replace if cracked, damaged, or leaking

How to Replace the Fuel Filters on a 6.4 Power Stroke

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• The primary fuel filter is located in the horizontal fuel conditioning module (HFCM) on the inside of the driver side frame rail between the fuel tank and the engine.

• The HFCM includes the primary fuel filter and the fuel-water separator. Drain the fuel-water-separator by placing a container beneath the drain valve and opening the 1/4 turn valve (yellow handle).

• To eliminate spilling fuel, we high recommend installing a section of 1/4" fuel line to the drain valve on the fuel-water separator; a container can then be placed on the ground as opposed to having to hold it in the air. Completely drain the fuel-water separator and properly dispose of the fuel that is collected.

• Remove the HFCM fuel filter using a 36 mm socket.

• Remove the fuel filter from the filter cap and install the new fuel filter and fuel filter o-ring.

• Apply a light coating of clean motor oil to the new o-ring and reinstall the filter/cap assembly. Torque to 25 N-m (~ 19 ft-lbs); do not overtighten, the plastic cap can be cracked easily.

• Remove the secondary fuel filter (engine mounted) located to the right of the oil filter housing using a 24 mm socket.

• Remove any remaining fuel from the fuel bowl using a syringe, turkey baster, suction gun, etc.

• Remove the used fuel filter from the filter cap and install the new one. In the image at left, you can see the mechanism at the top of the filter that "snaps" into the retainer on the fuel filter cap.

• Install the new o-ring on the fuel filter cap. Lightly lubricate seal with clean motor oil.

• Reinstall fuel filter into housing; torque to 14 N-m (~ 125 in-lbs)

• Cycle the key to the "run" position (as if to initiate the glow plug sequence) 3 - 5 times for 10 - 20 second intervals before starting engine; this will help fill the empty fuel filter housings. Check for leaks once the engine has been started.