Upper Structure Does Not Swing - Komatsu PC130-7 Shop Manual

TROUBLESHOOTING
H-22 Upper structure does not swing
Trouble (1) Upper structure does not swing in either direction.
Related
• Carry out the troubleshooting in working mode A.
information
Malfunction of swing hold-
1
ing brake solenoid valve
Malfunction of swing motor
2
(parking brake)
Possible causes
and standard
value in normal
Malfunction of swing motor
3
state
(safety valve)
Defective swing motor
4
(motor unit)
5 Defective swing machinery
Trouble (2) Upper structure swings only in 1 direction.
Related
• Carry out the troubleshooting in working mode A.
information
Malfunction of swing PPC
1
Possible causes
valve
and standard
value in normal
state
Malfunction of swing con-
2
trol valve (spool)
Defective seal of swing
3
motor (suction valve)
PC130-7
Cause Standard value in normal state/Remarks on troubleshooting
aPrepare with engine stopped, then run engine at high idling and carry
out troubleshooting.
Right work equipment control lever
The parking brake of the swing motor may have a malfunction. Check it
directly.
aPrepare with engine stopped, then run engine at high idling and carry
out troubleshooting.
Swing lock switch
aPrepare with engine stopped, then run engine at high idling and carry
out troubleshooting.
Swing lock switch
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.)
Cause Standard value in normal state/Remarks on troubleshooting
aPrepare with engine stopped, then run engine at high idling and carry
out troubleshooting.
Right work equipment control lever
The spool of the swing control valve may have a malfunction. Check it
directly.
The seal of the suction valve of the swing motor may be defective.
Check it directly.
Neutral position
SWING position
Left work equipment
control lever
Relieved in SWING
LOCK
position
Left work equipment
control lever
Relieved in SWING
LOCK
position
Neutral position
SWING position
Solenoid valve output pressure
0 MPa
2
{0 kg/cm }
2.84 – 3.43 MPa
2
{29 – 35 kg/cm }
Swing relief pressure
28.9 – 32.9 MPa
{295 – 335 kg/cm
Swing relief pressure
Max. 6 l/min
PPC valve output pressure
0 MPa
2
{0 kg/cm }
2.84 – 3.43 MPa
2
{29 – 35 kg/cm }
20-521
H-22
2
}
(1)