The 6.7-liter Cummins is the engine in the Dodge Ram's Heavy Duty line of pickup truck. The fuel filter doubles as a water separator and cleans imperfections and debris from the gas delivered to the engine. When the fuel filter becomes clogged or damaged, it translates into a noticeable decrease in performance and gas mileage. Easily accessible, the fuel filter can be changed in a short amount of time by a knowledgeable mechanic.
Park the vehicle on a flat surface and set the parking brake. Open the hood and disconnect the negative battery cable with a socket wrench. Unscrew the fuel cap to relieve pressure on the fuel lines.
Remove the eight screws from the fender well with a socket wrench. Push open the fender liner clamp and remove the fender liner.
Place a drip pan below the fuel filter. Open the drain valve on the bottom of the fuel filter and allow it to drain into the drip pan.
Disconnect the Water In Fuel (WIF) connector from the bottom of the fuel filter by gripping it firmly and pulling it free.
Attach a socket wrench to the bottom of the filter and unbolt the the fuel filter. Remove the fuel filter from the vehicle.
Reach into the housing assembly and remove the O-ring. Detach the drain hose from the old fuel filter.
Coat the new O-ring with a thin layer of motor oil. Install the new end seal and O-ring.
Attach the fuel filter and tighten it with a socket wrench attached to the bottom. Connect the WIF connector and drain hose to the new filter.
Set the fender well in place and replace the eight screws with a socket wrench. Reattach the clamp and tighten it by hand.
