Hydraulic Drift Of Work Equipment Is Large - Komatsu PC130-7 Shop Manual

TROUBLESHOOTING
H-11 Hydraulic drift of work equipment is large
Trouble (1) Hydraulic drift of boom is large.
Related
• Carry out the troubleshooting in working mode A.
information
Possible causes
Defective boom cylinder
and standard 1
(cylinder unit)
value in normal
state
Defective seal of boom cyl-
2
inder (lock valve)
Trouble (2) Hydraulic drift of arm is large.
Related
• Carry out the troubleshooting in working mode A.
information
Defective arm cylinder (cyl-
1
inder unit)
Possible causes
Defective seal of arm con-
and standard
2
trol lever (spool)
value in normal
Defective seal of arm con-
state
3
trol lever (suction valve)
Defective seal of central-
4
ized safety-suction valve
Trouble (3) Hydraulic drift of bucket is large.
Related
• Carry out the troubleshooting in working mode A.
information
Defective bucket cylinder
1
(cylinder unit)
Possible causes
Defective seal of bucket
2
and standard
control valve (spool)
value in normal
Defective seal of bucket
state
3 control valve (suction
valve)
Defective seal of central-
4
ized safety-suction valve
20-514
(1)
Cause Standard value in normal state/Remarks on troubleshooting
aPrepare with engine stopped, then run engine at high idling and carry
out troubleshooting.
Relieved in RAISE position
The seal of the lock valve of the boom cylinder may be defective. Check
it directly.
Cause Standard value in normal state/Remarks on troubleshooting
aPrepare with engine stopped, then run engine at high idling and carry
out troubleshooting.
Relieved in IN position
The seal of the arm control valve spool may be defective. Check it
directly.
The seal of the suction valve of the arm control valve may be defective.
Check it directly.
The seal of the centralized safety-suction valve of the control valve may
defective. Check it directly.
(A trouble of the centralized safety-suction valve have bad effects on
bucket.)
Cause Standard value in normal state/Remarks on troubleshooting
aPrepare with engine stopped, then run engine at high idling and carry
out troubleshooting.
Relieved in CURL position
The seal of the bucket control valve spool may be defective. Check it
directly.
The seal of the suction valve of the bucket control valve may be defec-
tive. Check it directly.
The seal of the centralized safety-suction valve of the control valve may
defective. Check it directly.
(A trouble of the centralized safety-suction valve have bad effects on
arm.)
Boom cylinder
Arm cylinder
Bucket cylinder
H-11
Leakage from cylinder
15 cc/min
Leakage from cylinder
15 cc/min
Leakage from cylinder
15 cc/min
PC130-7