6 Power Stroke Fuel Filter Replacement Procedures 6 power Stroke Fuel Filter Replacement How to Replace Fuel Filters on a 6 Power Stroke. The 6 Power Stroke features two fuel filters - the primary fuel filter is located in the HFCM, or Horizontal Fuel Conditioning Module, mounted to the driver side frame rail HFCM also contains the water-fuel [PDF] For 2003.5 MY and later F-250 through F-550 and Excursion For 2003.5 MY and later F-250 through F-550 and Excursion with the 6 DIT Power Stroke Diesel Engine Primary Fuel Filter Location under driver’s side frame 1. With a basin positioned below the fuel/water drain plug, remove fuel/water drain plug and drain until fuel stops. Note: Dispose of fuel properly. Use a 6mm allen wrench to loosen plug 3.