Engine Maintenance
104
Fuel Return Line Replacement
The fuel return lines (hoses) and end cap on the
fuel injection nozzles should be changed every
10,000 engine operating hours. The return line kit
(P/N 10-373) contains new return lines, clamps,
an end cap, and a decal like the one shown below.
The decal is located near the unit serial plate. The
date and engine hours must be entered on the
decal when the fuel return lines are changed.
Figure 165: Fuel Return Line Replacement Decal
Use the following procedure to replace the fuel
return lines and end cap.
1. Remove the clamps, the end cap, the short fuel
return lines between the injection nozzles, and
the long fuel return line from the injection
nozzle to the banjo fitting on the injection
pump.
2. Discard the old clamps, end cap, and fuel
return lines.
3. Install the end cap and clamp. Note that the
end cap has a larger OD than the other hoses
and requires the larger clamp.
4. Install the fuel return lines and clamps. It may
be necessary to adjust the banjo fitting slightly
to obtain the straightest routing for the long
return line.
5. Be sure all the fittings are tight and check for
leaks.
6. Write the date and engine hours on the decal.
Bleeding the Fuel System
If the engine runs out of fuel, repairs are made to
the fuel system, or if air gets into the system for
any other reason, the air must be bled out of the
fuel system.
To bleed air from the fuel system:
1. Turn the unit on and use the Output Test Mode
to energize the Run Relay, which energizes the
electric fuel pump. Refer to the appropriate
Diagnostic Manual for specific information
about the Service Test Mode.
2. Loosen the injection pump return line fitting
at the injection pump and run the electric fuel
pump until fuel is present at the injection
pump return line fitting.
3. Tighten the injection pump return line fitting
and exit the Output Test Mode.
4. Loosen the injection lines at the injection
nozzles.
5. Crank the engine until fuel appears at the
nozzles.
6. Tighten the injection lines.
7. Start the engine and observe the engine run for
a few minutes. If the engine fails to start, or
starts but stops in a few minutes, repeat the
procedure.
NOTE: MAKE SURE the fuel tank vent is kept
open. If the vent becomes clogged, a partial
vacuum develops in the tank, and this increases
the tendency for air to enter the system.
1.
End Cap
4.
Short Fuel Return Lines
2.
Larger Clamp
5.
Long Fuel Return Lines
3.
Smaller Clamps
Figure 166: Fuel Return Line Replacement
1
2
3
4
3
3
5
3
