Hydraulic Drift Of Work Equipment Is Large - Komatsu PC210-8 Shop Manual

40 Troubleshooting
H-11 Hydraulic drift of work equipment is large
Trouble (1) Hydraulic drift of boom is large.
Related
• Carry out all troubleshooting in power mode (P) of working mode.
information
1 Defective boom cylinder
Possible
causes and
standard value
in normal state
Defective seal of boom
2
control valve (lock valve)
Defective seal of safety
3
valve for lock valve
Trouble (2) Hydraulic drift of arm is large.
Related
• Carry out all troubleshooting in power mode (P) of working mode.
information
1 Defective arm cylinder
Defective seal of arm
2
Possible
control valve (spool)
causes and
Defective seal of arm con-
standard value
3 trol valve (pressure compen-
in normal state
sation valve)
Defective seal of arm
4
control valve (suction valve)
Defective seal of safety
5
valve for lock valve
PC210, 230, 240-8
Cause Standard value in normal state/Remarks on troubleshooting
a
Right work equipment control
Seal of lock valve of boom control valve may be defective. Check it
directly.
Seal of safety valve for lock valve may be defective. Check it
directly.
Cause Standard value in normal state/Remarks on troubleshooting
a
Left work equipment control lever
Seal of arm control valve spool may be defective. Check it directly.
Seal of pressure compensation valve of arm control valve may be
defective. Check it directly.
Seal of suction valve of arm control valve may be defective. Check
it directly.
a
Seal of safety valve for lock valve may be defective. Check it
directly.
Prepare with engine stopped, then run engine at high idling
and carry out troubleshooting.
lever
Boom raise relief
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Arm curl relief
This suction valve may be checked by replacing it with another
suction valve and seeing change of condition.
UEN00245-02
Leakage from boom cylinder
20 cc/min
Leakage from arm cylinder
20 cc/min
1
15