Komatsu PC130-7, Руководство по ремонту

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20-522
PC130-7
TROUBLESHOOTING
H-23 Swing acceleration or swing speed is low
Trouble (1) Swing acceleration or swing speed is low in both directions.
Related
information
• Carry out the troubleshooting in working mode A.
Possible causes
and standard
value in normal
state
Cause Standard value in normal state/Remarks on troubleshooting
1
Malfunction of swing con-
trol valve (pressure com-
pensation valve)
The pressure compensation valve of the swing control valve may have a
malfunction. Check it directly.
2
Malfunction of swing bleed
valve The swing bleed valve of the control valve may have a malfunction.
Check it directly.
3
Malfunction of swing motor
(parking brake) The parking brake of the swing motor may have a malfunction. Check it
directly.
4
Malfunction of swing motor
(safety valve)
a
Prepare with engine stopped, then run engine at high idling and carry
out troubleshooting.
Swing lock switch
Left work equipment
control lever
Swing relief pressure
LOCK position
Relieved in SWING
position
28.9 – 32.9 MPa
{295 – 335 kg/cm
2
}
5
Defective swing motor
(motor unit)
a
Prepare with engine stopped, then run engine at high idling and carry
out troubleshooting.
Swing lock switch
Left work equipment
control lever
Leakage from swing
motor
LOCK position
Relieved in SWING
position
Max. 6
l
/min
6 Defective swing machinery
The swing machinery may have a defect in it. Check it directly. (It may
be checked by abnormal sound, abnormal heating, metal chips in drain
oil, etc.)
Trouble (2) Swing acceleration or swing speed is low in only 1 direction.
Related
information
• Carry out the troubleshooting in working mode A.
Possible causes
and standard
value in normal
state
Cause Standard value in normal state/Remarks on troubleshooting
1
Malfunction of swing PPC
valve
a
Prepare with engine stopped, then run engine at high idling and carry
out troubleshooting.
Right work equipment control lever PPC valve output pressure
In NEUTRAL position
0 MPa
{0 kg/cm
2
}
In SWING position
2.84 – 3.43 MPa
{29 – 35 kg/cm
2
}
2
Clogging of swing PPC
slow return valve
The swing PPC slow return valve may be clogged. Check it directly.
3
Malfunction of swing con-
trol valve (spool) The spool of the swing control valve may have a malfunction. Check it
directly (including the stroke limiting mechanism).
4
Defective seal of swing
motor (suction valve) The seal of the suction valve of the swing motor may be defective.
Check it directly.
H-23
(1)