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TEST FUEL CIRCUIT FOR LEAKAGE
Tools for testing fuel circuit for leakage
Symbol Part No. Part name Q'ty Remarks
A
Commercially
available
Developer for dye penetrant (color
checker)
1
k
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. When the fuel circuit is test-
ed or any component is removed from or installed to it, check for fuel leakage according to the fol-
lowing procedure.
k
Place the machine on a level ground, and then lower the work equipment completely to the ground in
a stable posture. Set the lock lever to LOCK position, and then stop the engine.
k
Parts and oil are still very hot immediately after the engine is stopped. It may cause burn injury. Wait
for the temperature to go down, and then start the work.
Clean the engine and the parts around it, and degrease them in advance so that you can easily find the leakage
if any.
For testing the fuel system for leakage to perform troubleshooting, refer to this section.
METHOD FOR TESTING FUEL CIRCUIT FOR LEAKAGE
Testing method of fuel circuit for leakage at engine stopped
1.
Start the engine.
2.
Run the engine with fuel control dial at MIN (Low idle), and stop it after the engine automatic warm-up func-
tion is canceled automatically and engine speed is stabilized.
REMARK
• Turn the fuel control dial to MAX (High idle), the engine automatic warm-up function is canceled.
• For the condition of canceling the engine automatic warm-up function, see “ENGINE AUTOMATIC
WARM-UP SYSTEM”.
3.
Spray color checker A to the supply pump, common rail, injectors, and joints of the high-pressure piping.
4.
Check the fuel piping and component for fuel leakage.
• Check the high-pressure circuit for fuel leakage focusing on the area where the color checker A is
sprayed.
• If any fuel leakage is detected, repair it and perform the checks from step 1 again.
Testing method of fuel circuit for leakage at engine low idle
1.
Start the engine.
2.
Run the engine with fuel control dial at MIN (Low idle), and stop it after the engine automatic warm-up func-
tion is canceled automatically and engine speed is stabilized.
REMARK
• Turn the fuel control dial to MAX (High idle), the engine automatic warm-up function is canceled.
• For the condition of canceling the engine automatic warm-up function, see “ENGINE AUTOMATIC
WARM-UP SYSTEM”.
3.
Spray color checker A to the supply pump, common rail, injectors, and joints of the high-pressure piping.
4.
Start the engine, and set the fuel control dial to MIN (Low idle).
5.
Stop the engine and check the fuel piping and component for fuel leakage.
• Check the high-pressure circuit for fuel leakage focusing on the area where the color checker A is
sprayed.
• If any fuel leakage is detected, repair it and perform the checks from step 1 again.
30 TESTING AND ADJUSTING TEST FUEL CIRCUIT FOR LEAKAGE
PC500LC-10R 30-47