Engine Speed Lowers Extremely Or Engine Stalls - Komatsu PC130-7 Shop Manual

TROUBLESHOOTING
H-2 Engine speed lowers extremely or engine stalls
Trouble

• Engine speed lowers extremely or engine stalls.

Related
• Carry out the troubleshooting in working mode A.
information
Defective adjustment or
1 malfunction of main relief
valve
Defective adjustment or
2
malfunction of PC valve
Possible causes
and standard
value in normal
state
Defective adjustment or
3
malfunction of LS valve
Clogging of orifice or filter
4
in serve devices
5 Malfunction servo piston
PC130-7
Cause Standard value in normal state/Remarks on 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.
Measured oil 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 oil 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.
The orifices or filters in the pump servo devices may be clogged. Check
them directly.
The servo piston may have a malfunction. Check it directly.
Control levers
Measurement
conditions
Swing lock switch:
pressure
LOCK
Arm-IN circuit relieved
pressure
All levers in neutral
pressure
Almost same pressure
pressure
Main relief pressure
33.6 – 37.0 MPa
2
{343 – 378 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)
20-507
H-2
(1)