All Work Equipment Lack Power, Or Travel And Swing Speeds Are Slow - Komatsu ecot3 PC300LC-8 Shop Manual

SEN02633-03
H-1 All work equipment lack power, or travel and swing speeds are
slow
Trouble • Speed or power of whole work equipment, travel, and swing is low.
Related infor-
• Set the working mode in P-mode before start.
mation
1 Malfunction of unload valve
Defective adjustment or mal-
2
function of main relief valve
Malfunction of self pressure
3
Possible causes
reducing valve
and standard
value in normal
state
Defective adjustment or mal-
4
function of PC valve
5 Malfunction of LS-EPC valve
8
Cause Standard value in normal state/Remarks on troubleshooting
a
a
If oil pressure does not become normal after adjustment, main relief
valve may have malfunction or internal defect. Check main relief
valve directly.
a
a
Measured oil pres-
Pump discharge
pressure
PC valve output pres-
sure
If oil pressure does not become normal after adjustment, PC valve
may have malfunction or internal defect. Check PC valve directly.
a
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Control lever
All lever in neutral
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Control lever
Arm IN
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Control lever
All levers in neutral
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Measurement condi-
sure
Swing lock: ON
Arm IN relief
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Travel speed Travel lever
Lo
Hi Lifting operation
40 Troubleshooting
Unload pressure
3.9 ± 1.0 MPa
{40 ± 10 kg/cm
Main relief pressure
33.34 – 36.77 MPa
{340 – 375 kg/cm
Control circuit basic pressure
2.83 – 3.43 MPa
{29 – 35 kg/cm
Oil pressure ratio
tion
Approx. 3/5
LS-EPC output
pressure
Approx. 1.4 MPa
Neutral
{Approx. 14 kg/cm
0 MPa {0 kg/cm
PC300, 350-8
1
2
}
2
}
2
}
1
2
}
2
}