Engine Speed Sharply Drops Or Engine Stalls - Komatsu ecot3 PC300LC-8 Shop Manual

SEN02633-03
H-2 Engine speed sharply drops or engine stalls
Trouble • Engine speed lowers extremely or engine stalls.
Related infor-
• Set the working mode in P-mode before start.
mation
Defective adjustment or mal-
1
function of main relief valve
Defective adjustment or mal-
2
function of PC valve
Possible causes
and standard
value in normal
state
Defective adjustment or mal-
3
function of LS valve
Clogging of orifice or filter in
4
servo devices
5 Malfunction of servo piston
10
Cause Standard value in normal state/Remarks on troubleshooting
a
If oil pressure does not become normal after adjustment, main relief
valve may have malfunction or internal defect. Check main relief
valve directly.
a
Measured oil pres-
Pump discharge
pressure
PC valve output pres-
sure
If oil pressure does not become normal after adjustment, PC valve
may have malfunction or internal defect. Check PC valve directly.
a
Measured oil pres-
Pump discharge
pressure
LS valve output pres-
sure
If oil pressure does not become normal after adjustment, LS valve
may have malfunction or internal defect. Check LS valve directly.
Orifices or filters in pump servo devices may be clogged. Check
them directly.
Servo piston may have malfunction. Check it directly.
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Control lever
Arm IN
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
Measurement condi-
sure
Swing lock: ON
Arm IN relief
Prepare with engine stopped, then run engine at high idle and
carry out troubleshooting.
sure
All lever in neutral
Almost same pres-
40 Troubleshooting
Main relief pressure
33.34 – 36.77 MPa
{340 – 375 kg/cm
Oil pressure ratio
tion
1
Approx. 3/5
Oil pressure ratio
Travel with no load
(Lever operated
halfway)
1
sure
Approx. 3/5
PC300, 350-8
1
2
}