DAVCO Diesel Pro® and Fuel Pro® Models

m2+ m 47.02.001

    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. Shut down the engine, apply the parking brake, and chock the tires.
  2. Check the fuel level in the fuel filter. Replace the fuel/water separator element only when the filter element is completely covered. If the fuel level has reached the top of the filter element, follow the procedure below to replace the element.
  3. Put a clean receptacle under the fuel/water separator and attach a piece of hose to the drain valve, to direct fuel into the receptacle.
  4. Remove the vent cap, shown in Fig., to drain the fuel completely, then close the drain valve.

    1. Drain Valve

    2. Drain Valve Cap

    3. 120VAC Pre-Heater

    4. Inlet Port/Check Valve

    5. Lower Housing

    6. Bypass Valve

    7. 12VDC Pre-Heater

    8. Filter Element

    9. Spring

    10. Cover O-Ring

    11. Clear Cover

    12. Vent Cap O-Ring

    13. Vent Cap

    14. Collar

    Fig. 1, DAVCO Fuel Pro 487

  5. Using a DAVCO Collar Wrench, shown in Fig., remove the collar and clear cover.

    Fig. 2, Collar Wrench

  6. Remove the filter, cover O-ring, and vent cap O-ring. See Fig..
  7. Clean all threads and sealing surfaces very thoroughly. Even a small amount of dirt will prevent the fuel/water separator from sealing, and an air leak may result.

    8. Note:  Some models use a filter assembly that includes the bottom grommet.

  8. Install the new filter and grommet assembly and cover O-ring on the housing.
    Position the filter element so the key is lined up with the keyway on the separator plate of the housing. Use the arrow on the top of the endplate to align the filter. See Fig.. Ensure the filter element is fully seated by firmly pushing on the endplate. The filter should not rotate freely.

    1. Arrow (on the endplate)

    2. Keyway

    3. Separator Plate

    4. Key

    5. Endplate

    Fig. 3, Positioning the Filter Element

  9. Install the clear cover and the collar. Simultaneously apply downward pressure to the top of the clear cover until it is seated on the body of the lower housing and hand tighten the collar until it no longer spins freely. Using the collar wrench, tighten the cover 18 lbf·ft (24 N·m). This is equivalent to rotating the collar clockwise two or three additional ribs, depending on the specific filter model.
  10. Prime the system
    1. Ensure that the drain valve is closed.
    2. Fill the housing to the top of the filter element with clean diesel fuel.
    3. Install and hand-tighten the vent cap O-ring and vent cap.
    4. Start the engine. When the lubricating oil reaches its normal operating pressure, increase engine speed to high idle for one to two minutes to purge air from the system.
    5. While the engine is running, and after the air is purged from the system, loosen the vent cap until the fuel level falls to just above the collar, then hand-tighten the vent cap.
    6. Check for leaks and shut down the engine.
Note:
Parent topic: Fuel/Water Separator Element Check and Replacement
Document Number: 0000121057
Manual Publication Date: 2025-02-11
Topic Publication Date: 2024-11-06