Komatsu PC130-8 User Manual

SEN04124-00 40 Troubleshooting
24 PC130-8
H-23 Excessive overrun when stopping swing 1
Trouble • Excessive overrun when stopping swing.
(1) Overrun of upper structure is large in both direc-
tions.
Related
information
• Conduct the troubleshooting in working mode P.
Possible causes
and standard
value in normal
state
Cause Standard value in normal state/Remarks on troubleshooting
1 Swing motor defective
a Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
Left work equipment control
lever
Leakage from swing motor
Swing circuit relieved Below 6 l/min
Trouble • Excessive overrun when stopping swing.
(2) Overrun of upper structure is large in only one
direction.
Related
information
• Conduct the troubleshooting in working mode P.
Possible causes
and standard
value in normal
state
Cause Standard value in normal state/Remarks on troubleshooting
1
Malfunction of swing PPC
valve
a Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
Left work equipment control
lever
PPC valve output pressure
In NEUTRAL 0 MPa {0 kg/cm
2
}
Operated for swing
Above 2.7 MPa
{Above 28 kg/cm
2
}
2
Clogging of swing PPC slow
return valves
The swing PPC slow return valves may be clogged. Check them
directly. (They may be checked by exchanging with each other
and checking change of the phenomenon.)
3
Malfunction of swing control
valve (spool)
The spool of the swing control valve may have a malfunction.
Check it directly.
4
Defective adjustment or mal-
function of swing motor
(safety valve)
a Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
Swing lock switch
Left work equipment
control lever
Swing relief pressure
(Pump pressure)
ON
Swing circuits
relieved (separately
on both sides)
29.2 MPa
{298 kg/cm
2
}
5
Defective sealing of swing
motor (suction valve)
Sealing of the suction valve of the swing motor may be defective.
Check it directly.
6
Malfunction of swing motor
(reverse prevention valve)
Sealing of the reverse prevention valve of the swing motor may be
defective. Check it directly.
+1.5
–2.5
+15
–25

Komatsu PC130-8 Specifications

General

Brand	Komatsu
Model	PC130-8
Category	Excavators
Language	English