In Swing + Boom Raise Operation, Boom Moves Slowly; In Swing + Travel Operation, Travel Speed Drops Sharply - Komatsu ecot3 PC300LC-8 Shop Manual

SEN02633-03
H-16 In swing + boom RAISE operation, boom moves slowly
Trouble • When machine swings and raises boom simultaneously, boom rising speed is low.
Related infor-
• If speed of single boom raise operation is also low, carry out troubleshooting H-7 first.
mation
Possible causes
and standard
Malfunction or defective seal
value in normal
1
of LS selector valve
state
H-17 In swing + travel operation, travel speed drops sharply
Failure phe-
• In a compound operation of swing + travel, the travel speed drops sharply.
nomenon
Relative infor-
• If the travel speed is slow in the single operation of travel, carry out the H-19 check first.
mation
Presumed
cause and stan-
Malfunctioning of LS shuttle
dard value in
1
valve (left travel and swing)
normalcy
20
Cause Standard value in normal state/Remarks on troubleshooting
LS selector valve may have malfunction or defective seal. Check it
directly.
Cause Standard value in normalcy and references for troubleshooting
The LS shuttle valve in the left travel control valve or the swing con-
trol valve is presumed to malfunction. Check the valves themselves.
40 Troubleshooting
1
1
PC300, 350-8