Troubleshooting
Safety, Operation and Maintenance Manual - Aug 2012
6-11
SY115C9/135C/155H Crawler Hydraulic Excavator
4. Change hydraulic oil when the temperature
is high.
When hydraulic oil or other oil is warm, it
flows easily. In addition, the sludge can
also be drained out easily from the circuit
together with the oil, so it is best to change
the oil when it is still warm. When changing
the oil, as much as possible of the old hy-
draulic oil must be drained out. (Drain the
oil from the hydraulic tank; also drain the
oil from the
fi
lter and from the drain plug in
the circuit.) If any old oil is left, the contam-
inants and sludge in it will mix with the new
oil and will shorten the life of the hydraulic
oil.
5. Flushing operations
After disassembling and assembling
the equipment, or changing the oil, use
flushing oil to remove the contaminants,
sludge, and old oil from the hydraulic cir-
cuit. Normally,
fl
ushing is carried out twice:
primary
fl
ushing is carried out with
fl
ushing
oil, and secondary flushing is carried out
with the speci
fi
ed hydraulic oil.
6. Cleaning operations
After repairing the hydraulic equipment
(pump, control valve, etc.) or when run-
ning the machine, carry out oil cleaning to
remove the sludge or contaminants in the
hydraulic oil circuit. The oil cleaning equip-
ment is used to remove the ultra
fi
ne (about
3
μ
) particles that the
fi
lter built into the hy-
draulic equipment cannot remove, so it is
an extremely effective device.
ZX215-1000026
Flushing oil
ZX215-1000027
Fig. 6-3
Fig. 6-4