Komatsu PC210-8, Shop Manual

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40 Troubleshooting UEN00245-02
PC210, 230, 240-8
17
H-12 Time lag of work equipment is large 1
H-13 When part of work equipment is relieved singly, other parts of work
equipment move 1
Trouble
• Time lag of work equipment is large.
Related
information
• Carry out all troubleshooting in power mode (P) of working mode.
Possible
causes and
standard value
in normal state
Cause Standard value in normal state/Remarks on troubleshooting
1 Malfunction of LS-EPC valve
a
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Travel speed Travel lever
LS-EPC valve output
pressure
Lo Neutral
Approx. 2.9 MPa
{Approx. 30 kg/cm
2
}
Hi Operated
0 MPa
{0 kg/cm
2
}
2
Malfunction of control valve
(regeneration valve) [Boom
and arm only]
Regeneration valve of control valve may have malfunction. Check it
directly.
3
Malfunction of control valve
(safety-suction valve)
Safety-suction valve of control valve may have malfunction. Check
it directly.
a
This safety-suction valve may be checked by replacing it with
safety-suction valve of normal control valve and seeing
change of condition. (Set pressure of safety-suction valve for
boom head circuit is different, however.)
4
Malfunction of control valve
(pressure compensation
valve)
Pressure compensation valve of control valve may have malfunc-
tion. Check it directly.
Trouble
• When part of work equipment is relieved singly, other parts of work equipment move
Related
information
Possible
causes and
standard value
in normal state
Cause Standard value in normal state/Remarks on troubleshooting
1
Defective seal of control
valve (pressure compensa-
tion valve) on moving side
Seal of pressure compensation valve of control valve on moving
side may be defective. Check it directly.