How to Install a Fuel Water Separator

Fuel-water separators protect engines from damage caused by moisture in fuel. Separators are commonly used in diesel engine applications as well as in marine engine applications. Fuel water separators are installed on the fuel line prior to consumption by the engine. While fuel-water separators will not remove water absorbed by fuel, they do help prevent unabsorbed water from entering the engine. Exposure to water or storage of fuel near water sources increases the likelihood of water contamination. Condensation of airborne moisture on the inside of fuel tanks also contributes to water in fuel.

Things You'll Need

  • Pliers
  • Carpet knife
  • Golf tees
  • Round clamps the size of your fuel line
  • Drill
  • Screwdriver
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Instructions

    • 1

      Determine the inside diameter of your fuel line to select an appropriately sized fuel-water separator. The in-line separator fits snugly into the fuel line.

    • 2

      Identify a location at which the fuel line can be cut to install a fuel-water separator. Hold the separator along the fuel line to determine the fit. The fuel water separator should be placed near the engine on the fuel line in a location that engine vibrations will not damage the separator.

    • 3

      Cut the fuel line with the carpet knife to allow space for the fuel-water separator. If the fuel line does not accommodate the fuel-water separator easily, cut an additional section to provide space. Do not cut more fuel line than is required to allow the fuel-water separator to fit after installation. Push a golf tee into the fuel line to stop the flow of fuel, if necessary.

    • 4

      Determine the direction the fuel-water separator should be placed into the fuel line. The separator will have a direction "flow" arrow indicating which direction the fuel should be flowing.

    • 5

      Slide a hose clamp over each cut end of the fuel line. Insert the separator into the fuel line and slide the fuel line snugly against the separator. Most separators have a knob over which the fuel line must slip, helping prevent the fuel line from disengaging during use. Slide the hose clamp over the installed portion of the fuel-water separator and secure.

    • 6

      Mount the fuel-water separator in a secure location to avoid vibration damage, if necessary. Smaller in-line fuel separators do not require mounting. Larger separators will have mount holes. Use a drill to create holes at the mount point and a screwdriver to secure the screws holding the separator to the wall.

    • 7

      Pressurize the fuel system and inspect for leaks. Start the engine.