freightliner BUSINESS CLASS M2 100, Maintenance Manual

Page: 164 / 198

IMPORTANT: Some pressure may remain in the
fuel system between the solenoid valve and the
engine. Use caution when loosening fittings, as
a small amount of gas may leak out.
7. Put a clean receptacle under the filter assembly.
Using a 1-1/4-inch wrench, unscrew the filter
bowl from the filter housing.
8. Remove and discard the filter element.
9. Install a new filter element in the filter housing.
10. Inspect the O-ring on the filter housing for dam-
age or cracks. If necessary, replace the O-ring.
11. Install the filter bowl on the filter housing. Tighten
90 lbf·ft (122 N·m).
12. Close the bleed valve on the manifold and open
the manual fuel shutoff valve on the fuel panel.
13. Open the fuel cylinder shutoff valves.
14. Using a methane detector, leak test all fuel sys-
tem components between the fuel cylinders and
the solenoid valve. A bubble solution can be
used to pinpoint the exact location of leaks.
Repair or replace any leaking components.
15. Using the two capscrews removed previously,
install the access cover on the fill panel.
47–07 CNG Fuel Cylinder
Inspecting
Have a qualified inspector inspect compressed natu-
ral gas (CNG) fuel cylinders for damage or deteriora-
tion. Note cuts, cracks, gouges, abrasions, discolor-
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2
2
3
4
5
6
7
8
1
1. Fuel Panel Access
Cover
2. Capscrews (qty 2)
3. Wiring Harness
4. Pressure Relief Valve
and Cap
5. Coolant Outlet Line
6. Coolant Inlet Line
7. Fuel Inlet Line (to fuel
cylinders)
8. Fuel Outlet Line (to
engine)
Fig. 13, CNG Fuel Panel Assembly
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6
7
8
9
10
11
12
13
14
1
2
3
4
5
1. Coolant Inlet Port
2. Coolant Outlet Port
3. Pressure Relief Valve
4. Pressure Regulator
5. Wiring Harness
6. Manifold Bleed Valve
7. Manifold
8. Manual Fuel Shutoff
Valve
9. Fuel Fill Port
10. Filter Housing
11. Filter Bowl
12. Filter Drain Plug
13. Solenoid Valve
14. Fuel Line To Cylinders
Fig. 14, CNG Fuel Panel Components
Fuel
47
Business Class M2 Maintenance Manual, March 2018
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