Komatsu PC200-8M0, Shop Manual, Page: 908 / 1254

500 Troubleshooting of hydraulic and mechanical system (H-mode)
H-18 Travel speed is low
40-500
28
PC200, 200LC, 220, 220LC-8M0
SEN06139-00
H-18 Travel speed is low
Failure
q
Travel speed is low.
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
Malfunction of travel PPC
valve
a
Be ready with engine stopped, then troubleshoot with engine
high idle.
Travel lever PPC valve output pressure
Neutral
0 MPa
{0 kg/cm
2
}
Forward
Reverse
2.84 to 3.43 MPa
{29 to 35 kg/cm
2
}
2
Malfunction of self-pressure
reducing valve
a
Be ready with engine stopped, then troubleshoot with engine
high idle.
Control lever Control circuit source pressure
All levers in the neutral position
2.84 to 3.43 MPa
{29 to 35 kg/cm
2
}
3 Malfunction of LS-EPC valve
a
Be ready with engine stopped, then troubleshoot with engine
high idle.
Travel speed Travel lever
LS-EPC valve
output pressure
Lo Neutral
Approx. 2.9 MPa
{Approx. 30 kg/cm
2
}
Hi Operation
0 MPa
{0 kg/cm
2
}
4
Malfunction of travel control
valve (spool)
Spool of travel control valve may malfunction. Check it.
5
Malfunction of travel control
valve (pressure compensa-
tion valve)
Pressure compensation valve of travel control valve may malfunc-
tion. Check it.
6
Malfunction of travel control
valve (suction valve)
Suction valve of travel control valve may malfunction. Check it.
7
Malfunction of bucket control
valve (LS shuttle valve) LS shuttle valve of bucket control valve may have malfunction.
Check it.
8 Defective travel motor
a
Be ready with engine stopped, then troubleshoot with engine
high idle.
Travel lever Leakage from travel motor
Travel system relief 27.2
l
/min
9 Defective final drive
Final drive may have internal defect. Check it.
*
It may be checked by abnormal sound, abnormal heating,metal
chips in drain oil, etc.