Speed Or Power Of Whole Work Equipment, Swing, And Travel Is Low - Komatsu PC130-7 Shop Manual

TROUBLESHOOTING
H-1 Speed or power of whole work equipment, swing, and travel is low
Trouble

• Speed or power of whole work equipment, swing, and travel is low.

Related
• Carry out the troubleshooting in working mode A.
information
1 Defective unload valve
Defective adjustment or
2 malfunction of main relief
valve
Defective self-reducing
3
pressure valve
Possible causes
and standard
value in normal
state
Defective adjustment or
4
malfunction of PC valve
Defective adjustment or
5
malfunction of LS valve
6 Malfunction of servo piston The servo piston may have a malfunction. Check it directly.
7 Defective piston pump
20-506
(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
Arm-IN circuit relieved
If the oil pressure does not become normal after adjustment, the main
relief valve may have a malfunction or a defect in it. Check the main
relief valve directly.
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
Measured pump
discharge pressure
Pump discharge
PC valve output
If the oil pressure does not become normal after adjustment, the PC
valve may have a malfunction or a defect in it. Check the PC valve
directly.
aPrepare with engine stopped, then run engine at high idling and carry
out troubleshooting
Measured pump
discharge pressure
Pump discharge
LS valve output
If the oil pressure does not become normal after adjustment, the LS
valve may have a malfunction or a defect in it. Check the LS valve
directly.
If none of above causes is the cause of the trouble, the cause may be
lowering performance, malfunction, or internal defect of the piston
pump.
Control levers
All levers in neutral
Control levers
Control levers
All levers in neutral
Measurement
conditions
Swing lock switch:
pressure
LOCK
Arm-IN circuit relieved
pressure
All levers in neutral
pressure
Almost same pressure
pressure
Unload pressure
2.4 – 3.4 MPa
2
{25 – 35 kg/cm }
Main relief pressure
33.6 – 37.0 MPa
2
{343 – 378 kg/cm }
Control circuit basic pressure
2.84 – 3.43 MPa
2
{29 – 35 kg/cm }
Oil pressure ratio
1
0.6 (3/5)
Oil pressure ratio
Either track shoe
driven idle (Full stroke)
1
0.6 (3/5)
PC130-7
H-1