Komatsu PC220-8M0 User Manual

SEN06139-00
PC200, 200LC, 220, 220LC-8M0 40-500 11
500 Troubleshooting of hydraulic and mechanical system (H-mode)
H-2 Engine speed lowers significantly or engine stalls
H-2 Engine speed lowers significantly or engine stalls
Failure q Engine speed lowers significantly or engine stalls
Related infor-
mation
q Perform all troubleshooting with working mode in power mode (P).
Probable
causes and cri-
teria
Cause Criteria and troubleshooting procedure
1
Defective adjustment or mal-
function of main relief valve
a Be ready with engine stopped, then troubleshoot with engine
high idle.
Left work equipment control
lever
Main relief pressure
Arm IN relief
33.3 to 37.2 MPa
{340 to 380 kg/cm
2
}
If normal oil pressure is not obtained by adjustment, main relief
valve may malfunction or have internal defect. Check main relief
valve.
2
Malfunction of PC-EPC
valve
a Be ready with engine stopped, then troubleshoot with engine at
low speed and engine high idle.
Engine Control lever
PC-EPC valve out-
put pressure
Low idle
All levers in the neu-
tral position
Approx. 2.9 MPa
{Approx. 30 kg/cm
2
}
High idle
0.52 to 0.91 MPa
{5.3 to 9.3 kg/cm
2
}
3
Defective adjustment or mal-
function of PC valve
a Be ready with engine stopped, then troubleshoot with engine
high idle.
Measured oil pres-
sure
Measurement condi-
tions
Ratio of oil pressures
Pump discharge
pressure
Swing lock
Switch: ON
Arm IN relief
1
PC valve output pres-
sure
Approx. 0.6 (Approx.
3/5)
If normal oil pressure is not obtained after adjustment, PC valve
may malfunction or have internal defect. Check PC valve.
4
Defective adjustment or mal-
function of LS valve
a Be ready with engine stopped, then troubleshoot with engine
high idle.
Measured oil pres-
sure
Operation of levers and oil pressure ratio
All levers in the neu-
tral position
Run the track off
ground.
(lever at half stroke)
Pump discharge
pressure
Almost same pres-
sure
1
PC valve output pres-
sure
Approx. 0.6 (Approx.
3/5)
If normal oil pressure is not obtained by adjustment, the LS valve
may malfunction or have internal defect. Check LS valve.
5
Clogging of orifice or filter in
serve device
Orifices or filters in pump servo devices may be clogged. Check
them.
6 Malfunction of servo piston Servo piston may malfunction. Check it.

Komatsu PC220-8M0 Specifications

General

Brand	Komatsu
Model	PC220-8M0
Category	Excavators
Language	English