TK 56433-5-MM-EN
37
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 16.
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.
Figure 17.
Fuel Return Line Replacement
1.
End Cap
4.
Short Fuel Return Lines
2.
Larger Clamp
5.
Long Fuel Return Lines
3.
Smaller Clamps
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.
N
No
otte
e:: 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.
To bleed air from the fuel system:
1. Loosen the bleed screw about one turn.
Figure 18.
Injection Pump
1.
Bleed Screw
2.
Priming Pump
2. Unscrew the priming pump handle and manually
prime the fuel system until air bubbles are no
longer visible in the fuel coming out of the bleed
screw.
3. Tighten the bleed screw and screw the priming
pump handle back in.
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
