Detroit

p4 mm 47.02

Important: For chassis-mounted fuel filter replacement, refer to the engine manufacturer's service literature for replacement intervals.

The only maintenance necessary on an Detroit fuel/water separator is to replace the filter element. See Fig..

  1. Mounting Head

  2. Sight Bowl

  3. Electrical Connector for Bowl Heater

  4. Bowl Drain

Fig. 1, Detroit Fuel/Water Separator

    Warning: Fluid circulated through the fuel/water separator to heat the fuel may be diesel fuel returned from the engine, or engine coolant. Drain the fuel/water separator only when the engine and fluids have cooled. Draining it when the engine is hot could cause severe personal injury due to scalding.

    If returning fuel is released into the atmosphere, its vapors can ignite in the presence of any ignition source. Do not expose the fuel to, or work with the fuel system near, open flame or intense heat. To do so could cause fire, possibly resulting in serious personal injury or property damage.

  1. Drain off some fuel by loosening the vent plug and opening the drain valve.
  2. Disconnect the water sensor and heater connections if equipped.
  3. Remove the bowl by turning counterclockwise.
  4. Remove the element, bowl O-ring, and element o-ring. Dispose of them in an environmentally acceptable manner.
  5. Thoroughly clean all of the threads and sealing surfaces. Even a small amount of dirt will prevent the fuel/water separator from sealing, and an air leak may result.
  6. Apply a coating of clean fuel or motor oil to the new O-ring and to the new element o-ring.
  7. Insert the new element into the upper housing.
  8. Important: Do not use tools to tighten the bowl and element.

  9. Spin the bowl onto the onto the upper housing by hand only.
  10. Connect the water sensor and heater connectors if equipped.
  11. If equipped with a primer pump, prime the fuel/water separator as follows.
    1. Loosen the vent plug. Then operate the primer pump until the fuel purges at the vent plug.
    2. Close the vent plug.
  12. Start the engine and check for fuel leaks.
  13. Shut down the engine and correct any fuel leaks.
Note:
Document Number: 0000103335
Manual Publication Date: 2024-05-15
Topic Publication Date: 2025-03-11