Testing Fuel System For Leakage - Komatsu 114E-3 Series Shop Manual

SEN00455-01

Testing fuel system for leakage

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Very high pressure is generated in the high-
pressure circuit of the fuel system. If fuel
leaks while the engine is running, it is dan-
gerous since it can catch fire.
After testing the fuel system or removing
its parts, test it for fuel leakage according
to the following procedure.
a Clean and degrease the engine and the parts
around it in advance so that you can test it eas-
ily for fuel leakage.
1. Spray color checker (developer) over the fuel
supply pump, common rail, fuel injector, and
joints of the high-pressure piping.
2. Run the engine at speed below 1,000 rpm and
stop it after its speed is stabilized.
3. Inspect the fuel piping and devices for fuel
leakage.
a Check mainly around the high-pressure
circuit parts coated with the color checker
for fuel leakage.
a If any fuel leakage is detected, repair it
and inspect again from step 2.
4. Run the engine at low idle.
5. Inspect the fuel piping and devices for fuel
leakage.
a Check mainly around the high-pressure
circuit parts coated with the color checker
for fuel leakage.
a If any fuel leakage is detected, repair it
and inspect again from step 2.
6. Run the engine at high idle.
7. Inspect the fuel piping and devices for fuel
leakage.
a Check mainly around the high-pressure
circuit parts coated with the color checker
for fuel leakage.
a If any fuel leakage is detected, repair it
and inspect again from step 2.
8. Run the engine at high idle and load it.
a When checking while the components to
be checked are mounted on the machine,
stall the torque converter or relieve the
hydraulic pump.
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9. Inspect the fuel piping and devices for fuel
leakage.
a Check mainly around the high-pressure
circuit parts coated with the color checker
for fuel leakage.
a If any fuel leakage is detected, repair it
and inspect again from step 2.
a If no fuel leakage is detected, check is
completed.
30 Testing and adjusting
114E-3 Series