Komatsu 80001 User Manual

40 Troubleshooting SEN04124-00
PC130-8
7
H-2 Engine speed sharply drops or engine stalls 1
Trouble • Engine speed sharply drops or the engine stalls.
Related
information
• Conduct the troubleshooting in working mode P.
Possible causes
and standard
value in normal
state
Cause Standard value in normal state/Remarks on troubleshooting
1
Defective adjustment or
operation of main relief valve
(power-up mode)
a Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
Control lever Main relief pressure
Arm relieved in IN direction
34.8 MPa
{355 kg/cm
2
}
If the oil pressure cannot be set normally by adjustment, the main
relief valve may be malfunction or may have an internal defect.
Check the main relief valve directly.
2
Defective adjustment or
operation of PC valve
a Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
Measured oil
pressure
Measurement
conditions
Oil pressure ratio
Pump discharge
pressure
Swing lock: ON
Arm: Relieved in IN
direction
1
PC valve output
pressure
Approx. 0.6
(Approx. 3/5)
If the oil pressure cannot be set normally by adjustment, the PC
valve may be malfunction or may have an internal defect. Check
the PC valve directly.
3
Defective adjustment or
operation of LS valve
Measured oil
pressure
Oil pressure ratio
All levers in
NEUTRAL
Bucket curled
(Lever at stroke end)
Pump discharge
pressure
Almost same
pressure
1
LS valve output
pressure
Approx. 0.6
(Approx. 3/5)
If the oil pressure cannot be set normally by adjustment, the LS
valve may be malfunction or may have an internal defect. Check
the LS valve directly.
4
Orifice or filter in servo
equipment clogged
The orifice or filter in the pump servo equipment is suspected of
clogging. Check the equipment itself.
5 Malfunction of servo piston The servo piston may have malfunction. Check it directly.
+2.0
–1.0
+20
–10

Komatsu 80001 Specifications

General

Brand	Komatsu
Model	80001
Category	Excavators
Language	English