Komatsu PC130-7, Shop Manual

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20-508
PC130-7
TROUBLESHOOTING
H-3 Work equipment, swing, and travel systems do not work
H-4 Abnormal sound comes out from around hydraulic pump
Trouble • Work equipment, swing, and travel systems do not work.
Related
information
• Carry out the troubleshooting in working mode A.
Possible causes
and standard
value in normal
state
Cause Standard value in normal state/Remarks on troubleshooting
1
Malfunction of PPC lock
solenoid valve
a
Prepare with engine stopped, then run engine at high idling and carry
out troubleshooting.
Safety lock lever Solenoid valve output pressure
LOCK
0 MPa
{0 kg/cm
2
}
FREE
2.84 – 3.43 MPa
{29 – 35 kg/cm
2
}
2
Malfunction of self-reduc-
ing pressure valve
a
Prepare with engine stopped, then run engine at high idling and carry
out troubleshooting.
Control levers Control circuit basic pressure
All levers in neutral
2.84 – 3.43 MPa
{29 – 35 kg/cm
2
}
3 Malfunction of piston pump
The piston pump may have a malfunction or has an internal defect.
Check it by the following method.
• Remove the pump discharge pressure pickup plug and crank the en-
gine. If the oil flows out at this time, the piston pump is normal.
4 Defective damper
The pump shaft may not rotate because of an defect in the damper.
Check the damper directly.
Trouble • Abnormal sound comes out from around hydraulic pump.
Related
information
• Carry out the troubleshooting in working mode A.
Possible causes
and standard
value in normal
state
Cause Standard value in normal state/Remarks on troubleshooting
1
Lowering of hydraulic oil
level
Check it directly.
2 Defective hydraulic oil Hydraulic oil may contain air. Check hydraulic oil directly.
3
Clogging of hydraulic tank
cap Negative pressure may be applied to the hydraulic tank because of clog-
ging of the hydraulic tank cap. Check the cap directly.
4
Clogging of hydraulic tank
strainer Negative pressure may be applied to the suction circuit because of clog-
ging of the hydraulic tank strainer. Check the strainer directly.
5 Defective piston pump The piston pump may have a defect in it. Check it directly.
H-3, H-4
(1)