Komatsu ecot3 PC300-8, Shop Manual

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30 Testing and adjusting
26
PC300, 350-8
SEN02625-06
Testing fuel return rate and
leakage
a
Testing tools for leakage from pressure limiter
and return rate from injector
k Park the machine in a level ground and lower
the work equipment to the ground.
1. Testing supply pump return rate
1) Disconnect return tube (1) of the supply
pump.
a
Before starting the work, remove the re-
turn hose from the aftercooler so that it
may not interfere with the inspection.
2) Connect testing tool H1 to the supply pump
side, and insert its tip into measuring cylinder
H3 .
3) Connect blocking tool H2 to the fuel return
connector side to prevent leakage of the fuel.
4) Install the aftercooler hose, run the engine at
low idle and then measure the return rate
from the supply pump.
a
If the return rate from the supply pump is
in the following range, it is normal.
k If the engine cannot be started, you
may measure the fuel return rate while
rotating the engine with the starting
motor. Do not rotate for more than 30
seconds continuously, however, for
protection of the starting motor.
5) After finishing testing, remove the testing
tools and return the removed parts.
3
Joint bolt (M14):
36
±
5 Nm {3.67
±
0.51 kgm}
2. Testing leakage from pressure limiter
a
Before displaying failure code [ CA449 ], its
troubleshooting must be done beforehand.
1) Disconnect joint bolt (3) of return tube (2) of
the pressure limiter.
2) Screw in adapter H2 together with return
tube (2), and insert its tip into measuring
cylinder
H3 .
3) Connect blocking tool H1 to the return tube
joint connection of the cylinder block side to
prevent leakage of the fuel.
Symbol Part No. Part name
H
1 795-790-4800 Hose KIT
2 795-790-6700 Adapter
3
Commercially
available
Measuring cylinder
At low idle Max. 300 cc/30 sec.
At cranking Max. 200 cc/30 sec.