freightliner M2 Plus Maintenance Manual page 142

47
5. Apply a coating of clean fuel or motor oil to the
new O-ring and element seal.
6. Spin the bowl onto the new element, then spin
them both onto the filter head, snugly, by hand
only.
IMPORTANT: Do not use tools to tighten the
bowl and element.
7. Connect the water sensor and heater connectors
if equipped.
8. If equipped with a primer pump, prime the
fuel/water separator.
8.1 Loosen the vent plug. Then operate the
primer pump until the fuel purges at the
vent plug.
8.2 Close the vent plug.
9. Start the engine and check for fuel leaks.
10. Shut down the engine and correct any fuel leaks.
DAVCO Diesel Pro® and Fuel
Pro® Models
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.
47/2
4. Remove the vent cap, shown in
the fuel completely, then close the drain valve.
5. Using a collar wrench, shown in
the collar and clear cover.
6. Remove the filter, cover O-ring, and vent cap
O-ring. See Fig. 2.
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.
NOTE: Some models use a filter assembly that
includes the bottom grommet.
8. Install the new filter and grommet and cover
O-ring on the housing.
For filter elements that have an alignment
feature, 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
the filter element is fully seated by firmly pushing
on the endplate. The filter should not rotate
freely.
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
10.1 Ensure that the drain valve is closed.
10.2 Fill the housing to the top of the filter
element with clean diesel fuel.
10.3 Install and hand-tighten the vent cap
O-ring and vent cap.
10.4 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.
10.5 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
Business Class M2 Plus Maintenance Manual, 02/10/2023
Fuel
Fig. 2, to drain
Fig. 3, remove
Fig. 4. Ensure