Komatsu PC200-8M0, Shop Manual, Page: 919 / 1254

SEN06139-00
PC200, 200LC, 220, 220LC-8M0 40-500
39
500 Troubleshooting of hydraulic and mechanical system (H-mode)
H-27 Hydraulic drift of swing is large
H-27 Hydraulic drift of swing is large
Failure (1) Swing drift on a slope is large (when swing holding brake is being applied)
Related infor-
mation
q When swing lock switch is turned to ON position or when swing brake cancel switch is set to normal
position, swing holding brake is applied and swinging motion of upper structure is stopped with disc
brake.
q
Perform all troubleshooting with working mode in power mode (P).
Probable
causes and cri-
teria
Cause Criteria and troubleshooting procedure
1
Malfunction of swing holding
brake solenoid valve
a
Be ready with engine stopped, then troubleshoot with engine
high idle.
Left work equipment control
lever
Output pressure of swing holding
brake
solenoid valve
Neutral
0 MPa
{0 kg/cm
2
}
Left swing
Right swing
Approx. 2.9 MPa
{Approx. 30 kg/cm
2
}
2
Malfunction of swing motor
(swing holding brake)
Swing brake may malfunction. Check it.
Failure (2) Swing drift on a slope is large (when swing brake is being released).
Related infor-
mation
q
When swing holding brake release switch is in release position, swing holding brake is released
andupper structure is secured by only hydraulic pressure.
q
Perform all troubleshooting with working mode in power mode (P).
Probable
causes and cri-
teria
Cause Criteria and troubleshooting procedure
1
Malfunction or defective seal
of swing control valve (spool) Swingcontrolvalve spool may have malfunction or defective seal.
Check it.
2
Defective seal of swing con-
trol valve (pressure compen-
sation valve)
Sealofpressure compensation valve of swing control valve may be
defective. Check it.
3
Defective seal of swing
motor (safety valve) Sealing for safety valve of swing motor may be defective .Check
the valve.
4
Defective seal of swing
motor (suction valve) Sealing of the suction valve of the swing motor may be defective.
Check it.
5
Defective sealing of swing
motor (check valve)
Sealing for check valve of swing motor may be defective . Check it.
6
Defective seaing for swing
motor (shockless valve) Sealing for shockless valve of swing motor may be defective.
Check it.