Work Equipment, Swing, And Travel Systems Do Not Work; Abnormal Sound Comes Out From Around Hydraulic Pump - Komatsu PC130-7 Shop Manual

TROUBLESHOOTING
H-3 Work equipment, swing, and travel systems do not work
Trouble

• Work equipment, swing, and travel systems do not work.

Related
• Carry out the troubleshooting in working mode A.
information
Malfunction of PPC lock
1
solenoid valve
Possible causes
and standard
value in normal
Malfunction of self-reduc-
state
2
ing pressure valve
3 Malfunction of piston pump
4 Defective damper
H-4 Abnormal sound comes out from around hydraulic pump
Trouble

• Abnormal sound comes out from around hydraulic pump.

Related
• Carry out the troubleshooting in working mode A.
information
Lowering of hydraulic oil
1
level
Possible causes
2 Defective hydraulic oil
and standard
Clogging of hydraulic tank
value in normal
3
cap
state
Clogging of hydraulic tank
4
strainer
5 Defective piston pump
20-508
(1)
Cause Standard value in normal state/Remarks on troubleshooting
aPrepare with engine stopped, then run engine at high idling and carry
out troubleshooting.
aPrepare with engine stopped, then run engine at high idling and carry
out troubleshooting.
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.
The pump shaft may not rotate because of an defect in the damper.
Check the damper directly.
Cause Standard value in normal state/Remarks on troubleshooting
Check it directly.
Hydraulic oil may contain air. Check hydraulic oil directly.
Negative pressure may be applied to the hydraulic tank because of clog-
ging of the hydraulic tank cap. Check the cap directly.
Negative pressure may be applied to the suction circuit because of clog-
ging of the hydraulic tank strainer. Check the strainer directly.
The piston pump may have a defect in it. Check it directly.
Safety lock lever
LOCK
FREE
Control levers
All levers in neutral
H-3, H-4
Solenoid valve output pressure
0 MPa
2
{0 kg/cm }
2.84 – 3.43 MPa
2
{29 – 35 kg/cm }
Control circuit basic pressure
2.84 – 3.43 MPa
2
{29 – 35 kg/cm }
PC130-7