No Work Equipment, Swing Or Travel Move; Abnormal Noise Is Heard From Around Hydraulic Pump - Komatsu ecot3 PC300LC-8 Shop Manual

40 Troubleshooting
H-3 No work equipment, swing or travel move
Trouble • All work equipment, swing, and travel mechanism do not move.
Related infor-
• Set the working mode in P-mode before start.
mation
Malfunction of PPC lock
1
solenoid valve
Possible causes
and standard
value in normal
Malfunction of self pressure
2
state
reducing valve
3 Defective piston pump
4 Defective damper
H-4 Abnormal noise is heard from around hydraulic pump
Failure phe-
• An abnormal noise is heard from around hydraulic pump.
nomenon
Relative infor-
mation
1 Hydraulic oil level lowered
2 Quality of hydraulic oil bad
Presumed
3 Hydraulic tank cap clogged
cause and stan-
dard value in
normalcy
Hydraulic tank strainer
4
clogged
5 Piston pump defective
PC300, 350-8
Cause Standard value in normal state/Remarks on troubleshooting
a
a
Piston pump may have malfunction or internal defect. Check it by
following method.
• Crank the engine with oil pressure measurement plug removed.
If oil flows out, the piston pump is normal.
Pump shaft may not revolve because of defect in damper. Check
damper directly.
Cause Standard value in normalcy and references for troubleshooting
Make a visual check.
Air may have get mixed with the oil. Make a visual check.
It is presumed that the cap of hydraulic tank is clogged, thereby
causing negative pressure inside the tank. Make a visual check.
It is presumed that the strainer in the hydraulic tank is clogged,
thereby causing negative pressure in the suction circuit. Make a
visual check.
The piston pump is suspected of an internal failure. Check the pump
itself.
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Lock lever
Lock
Released
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Control lever
All levers in neutral
SEN02633-03
Solenoid output pressure
2
0 MPa {0 kg/cm }
2.84 – 3.43 MPa
2
{29 – 35 kg/cm }
Control circuit basic pressure
2.83 – 3.43 MPa
2
}
{29 – 35 kg/cm
1
1
11