Hydraulic Drift Of Swing Is Large - Komatsu PC210-8 Shop Manual

UEN00245-02
H-28 Hydraulic drift of swing is large
Trouble (1) Hydraulic drift of swing is large (when swing holding brake is applied).
• When swing lock switch is turned ON or when swing holding brake release switch is in normal posi-
Related
tion, swing holding brake operates and upper structure is fixed with disc brake.
information
• Carry out all troubleshooting in power mode (P) of working mode.
Possible
Malfunction of swing holding
causes and 1
brake solenoid valve
standard value
in normal state
Malfunction of swing motor
2
(parking brake)
Trouble (2) Hydraulic drift of swing is large (when swing holding brake is released).
• When swing holding brake release switch is in release position, swing holding brake is released and
Related
upper structure is secured by only hydraulic pressure.
information
• Carry out all troubleshooting in power mode (P) of working mode.
Malfunction or defective seal
1
of swing control valve (spool)
Defective seal of swing con-
2 trol valve (pressure compen-
sation valve)
Possible
causes and Defective seal of swing
3
standard value motor (safety valve)
in normal state
Defective seal of swing
4
motor (suction valve)
Defective seal of swing
5
motor (check valve)
Defective seal of swing
6
motor (shockless valve)
30
Cause Standard value in normal state/Remarks on troubleshooting
a
Left work equipment control lever
Parking brake of swing motor may have malfunction. Check it
directly.
Cause Standard value in normal state/Remarks on troubleshooting
Swing control valve spool may have malfunction or defective seal.
Check it directly.
Seal of pressure compensation valve of swing control valve may be
defective. Check it directly.
Seal of safety valve of swing motor may be defective. Check it
directly.
Seal of suction valve of swing motor may be defective. Check it
directly.
Seal of check valve of swing motor may be defective. Check it
directly.
Seal of shockless valve of swing motor may be defective. Check it
directly.
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Neutral
Left swing
Right swing
40 Troubleshooting
Swing holding brake
solenoid valve output pressure
0 MPa
2
{0 kg/cm }
2.9 MPa
{30 kg/cm 2 }
PC210, 230, 240-8
1