Testing Fuel Circuit For Leakage - Komatsu PC88MR-10 Shop Manual

30 Testing and adjusting
Engine and cooling system

Testing fuel circuit for leakage

a Testing tools
Sym-
Part No.
bol
Commercially
Y
available
Very high pressure is generated in the high-
pressure circuit of the fuel system. If fuel
leaks while the engine is running, it presents
a serious danger that could result in a fire.
After testing the fuel system and removing or
installing the tools for the test, test it for fuel
leakage according to the following procedure.
Place the machine on a level ground and
lower the work equipment to the ground.
a Clean and degrease the engine and the parts
around it in advance so that you can check it
easily for fuel leakage.
Testing
(PC88MR-AD00-364-K-00-A)
1. Spray color checker (developer) Y to the fuel
supply pump, common rail, fuel injectors, and
joints of the high-pressure fuel piping.
2. Start the engine, keep its speed at 1,200 rpm or
below, and stop it when its speed is stabilized.
3. Check the fuel piping and devices for fuel
leakage.
a Check the high-pressure circuit for fuel
leakage focusing on the area where color
checker Y is sprayed.
a If any fuel leakage is detected, repair it and
perform the checks from step 1 again.
4. Start the engine, and keep it running at low idle.
5. Check the fuel piping and devices for fuel
leakage.
a Check the high-pressure circuit for fuel
leakage focusing on the area where color
checker Y is sprayed.
a If any fuel leakage is detected, repair it and
perform the checks from step 1 again.
6. Start the engine, and keep it running at high idle.
7. Check the fuel piping and devices for fuel
leakage.
a Check the high-pressure circuit for fuel
leakage focusing on the area where color
checker Y is sprayed.
a If any fuel leakage is detected, repair it and
perform the checks from step 1 again.
8. Start the engine and keep it running at high idle,
then apply a load to the engine.
30-22
(PC138-AD00-360-K-00-A)
Part name
Developer
for dye penetrant check
(color checker)
a Relieve the arm circuit at the arm IN stroke
end.
9. Check the fuel piping and devices for fuel
leakage.
a Check the high-pressure circuit for fuel
leakage focusing on the area where color
checker Y is sprayed.
a If any fuel leakage is detected, repair it and
perform the checks from step 1 again.
a If no fuel leakage is detected, check is
complete.
PC88MR-10