freightliner M2 Plus Maintenance Manual page 144

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06/09/2022
1. Mounting Head
Fig. 5, 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.
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f470689
2. Sight Bowl
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.
IMPORTANT: Do not use tools to tighten the
bowl and element.
8. Spin the bowl onto the onto the upper housing
by hand only.
9. Connect the water sensor and heater connectors
if equipped.
10. If equipped with a primer pump, prime the
fuel/water separator as follows.
10.1 Loosen the vent plug. Then operate the
primer pump until the fuel purges at the
vent plug.
10.2 Close the vent plug.
11. Start the engine and check for fuel leaks.
12. Shut down the engine and correct any fuel leaks.
47–03 LNG Fuel System
Inspecting
WARNING
Natural gas is highly flammable. See the safety
precautions listed in Chapter 16 of the Business
Class® M2 Plus Driver's Manual or Group 47 of
the Business Class M2 Plus Workshop Manual.
Failure to observe these precautions could lead to
the ignition of the natural gas, which could cause
serious bodily injury or death.
The following inspections must be performed by a
qualified technician, in accordance with the
manufacturer's established inspection criteria.
All tank components should be allowed to defrost
before conducting the following inspections.
NOTICE
Do not use a high-pressure washer or steam
cleaner on natural gas fuel system plumbing
Business Class M2 Plus Maintenance Manual, 02/10/2023
Fuel