Komatsu PC400LC-5 Operation & Maintenance Manual page 257

36. PRECAUTIONS FOR MACHINE OPERATION
Scraping-down operations are prohibited.
Never use the front bucket of a bottom-dump bucket to scrap
down rocks or soil.
AEOSSSOO
Digging rocky ground
It
is better to excavate hard rocky ground after breaking it up by
some other means.
This will not only reduce damage to the machine but make for better
economy.
Phenomena that do not indicate failure
Note that the following phenomena are not faults:
l
The arm may sometimes stop when the bucket teeth become
more or less horizontal.
l At the beginning and end of a swinging, a noise may sometimes
be emitted from the brake valve.
l When descending a steep slope at low speed, a noise may
sometimes be emitted from the travel motor.
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