Draining; Replacing - Mercury TDI 3.0L Owner's Operation And Maintenance Manual

Section 4 - Maintenance
Water entering the fuel injection system will cause corrosion and rusting of the injectors and other components, disabling the
fuel injection system. Check daily for water in the water‑separating fuel filter and have the engine inspected immediately if
there is evidence of water in the fuel system.
IMPORTANT: Use a suitable container to collect fuel. Clean up any spills immediately and dispose of fuel in a safe manner in
accordance with all local, federal, and international regulations.
The engine‑mounted water‑separating fine element fuel filter is equipped with a water‑in‑fuel sensor that should alert the
operator when water is present in the filter. This fuel filter needs to be replaced at specified intervals or whenever water is
detected in the fuel, whichever comes first.
The operator may be alerted that the water‑in‑fuel sensor has detected water in the fuel, if the boat is equipped with the proper
instrumentation:
• Instrument notification (if equipped)
• Indicator lamp (if equipped)
When the engine is equipped with a remote mounted primary filter, it should be drained or replaced at specified intervals, or
whenever water is detected in the engine‑mounted fuel filter.

Draining

The engine‑mounted water‑separating fuel filter can be drained of water and sediment by removing the water‑in‑fuel sending
unit located on the bottom of the filter.
NOTE: To ensure complete draining in warm weather, drain the filter before starting daily operations. In cold weather, where
there is a possibility that the condensed water will freeze, drain the filter shortly after the end of daily operations.
NOTE: Place a suitable container under the fuel filter to catch contaminated fuel or water. Dispose of fuel and old filters in a
safe manner in accordance with all local, federal, and international regulations.
1. Place a suitable container under the water‑separating fine element fuel filter.
2. Disconnect the water‑in‑fuel sensor harness connector.
3. Remove the water‑in‑fuel sensor from the bottom of the filter.
4. Unscrew the bleed screw.
5. Drain the filter until the fuel is free of debris and water.
6. Install the water‑in‑fuel sensor and tighten securely.
7. Connect the water‑in‑fuel harness connector.
8. Install the bleed screw and tighten securely.
9. Push on the primer pump on top of the fuel filter until increased resistance is felt. Increased resistance will indicate the fuel
system has been filled with fuel.
a

Replacing

Performing service or maintenance without first disconnecting the battery can cause product damage, personal injury, or
death due to fire, explosion, electrical shock, or unexpected engine starting. Always disconnect the battery cables from the
battery before maintaining, servicing, installing, or removing engine or drive components.
IMPORTANT: The fine element fuel filter cannot be cleaned and reused. It must be replaced.
1. Disconnect both battery cables from the battery.
Page 58
a - Primer pump
b - Bleed screw
b
c - Fine element fuel filter
d - Water‑in‑fuel sensor
c
d
52259
NOTICE
WARNING
!
90-8M0145546 MAY 2018
eng