Upper Structure Does Not Swing - Komatsu PC210-8 Shop Manual

40 Troubleshooting
H-23 Upper structure does not swing
Trouble (1) Upper structure does not swing in either direction.
Related
• Carry out all troubleshooting in power mode (P) of working mode.
information
Malfunction of swing holding
1
brake solenoid valve
Malfunction of swing control
2
valve (spool)
Malfunction of swing motor
3
(parking brake)
Possible
causes and
standard value
in normal state
Defective adjustment or
4 malfunction of swing motor
(safety valve)
5 Defective swing motor
6 Defective swing machinery
PC210, 230, 240-8
Cause Standard value in normal state/Remarks on troubleshooting
a
Left work equipment control lever
Spool of swing control valve may have malfunction. Check it
directly.
Parking brake of swing motor may have malfunction. Check it
directly.
a
Swing lock switch
If oil pressure does not become normal after adjustment, swing
motor safety valve may have malfunction or internal defect. Check
safety valve directly.
a
Swing lock switch
Swing machinery may have internal defect. Check it directly.
a
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Neutral
Left swing
Right swing
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Left work equipment
control lever
ON Swing relief
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Left work equipment
control lever
ON Swing relief
It may be checked by abnormal sound, abnormal heating,
metal chips in drain oil, etc.
UEN00245-02
Swing holding brake
solenoid valve output pressure
0 MPa
2
{0 kg/cm }
2.9 MPa
2
{30 kg/cm }
Swing relief pressure
28.9 – 32.9 MPa
{295 – 335 kg/cm
Leakage from swing
motor
Max. 10 l/min
1
2
}
25