Time Lag Of Work Equipment Is Large; Work Equipment Loaded More Is Slower During Compound Operation; Boom Raise Speed Is Low In Compound Operation Of Swing + Boom Raise - Komatsu Galeo PC138US-8 Shop Manual

40 Troubleshooting
H-11 Time lag of work equipment is large
Trouble

• Time lag of work equipment is large.

Related
• Conduct the troubleshooting in working mode P.
information
Possible causes Malfunction of control valve
and standard 1 (regeneration valve) [Boom
value in normal and arm]
state
Malfunction of control valve
2
(suction valve)
H-12 Work equipment loaded more is slower during compound
operation
Trouble

• Work equipment loaded more is slower during compound operation.

Related
—
information
Possible causes
and standard
Malfunction of pressure com-
value in normal
1 pensation valve of work
state
equipment loaded less
H-13 Boom RAISE speed is low in compound operation of swing +
boom RAISE
Trouble

• Boom RAISE speed is low in compound operation of swing + boom RAISE.

Related • If the speed of single operation of the boom RAISE speed is slow, conduct troubleshooting for H-7
information first.
Possible causes
and standard
Malfunction or defective
value in normal
1
sealing of LS selector valve
state
PC138US, USLC-8
Cause Standard value in normal state/Remarks on troubleshooting
The regeneration valve of the control valve may have a malfunc-
tion. Check it directly.
The suction valve of the control valve (on the head side) may have
a malfunction. Check it directly.
Cause Standard value in normal state/Remarks on troubleshooting
The pressure compensation valve of the work equipment loaded
less may have a malfunction. Check it directly.
Compound operation
Boom RAISE +
Boom RAISE +
Boom RAISE +
Boom LOWER +
Cause Standard value in normal state/Remarks on troubleshooting
The LS selector valve of the control valve may have a malfunction
or its sealing may be defective. Check it directly.
More loaded side
Arm IN
Arm OUT
Bucket CURL
Arm IN +
Bucket CURL
Arm OUT
SEN02468-01
Less loaded side
Boom Arm
Arm Boom
Boom Bucket
Arm Bucket
Arm Boom
1
1
1
15