Machine Is Hard To Steer Or Travel Power Is Low - Komatsu PC200-8M0 Shop Manual

500 Troubleshooting of hydraulic and mechanical system (H-mode)
H-19 Machine is hard to steer or travel power is low
H-19 Machine is hard to steer or travel power is low
q
Failure

Machine is hard to steer or travel power is low

Related infor-
q
Perform all troubleshooting with working mode in power mode (P).
mation
Malfunction of travel PPC
1
valve (steering spool)
Malfunction of travel junc-
2
tion solenoid valve
Malfunction of travel junc-
3
tion valve
Malfunction of merge-divider
4
main EPC valve
Malfunction of merge-divider
5
Probable
LS-EPC valve
causes and cri-
Malfunction of merge-divider
teria
6
main valve
Malfunction of merge-divider
7
LS valve
Malfunction of travel control
8
valve (spool)
Malfunction of travel control
9 valve (pressure compensa-
tion valve)
Malfunction of travel control
10
valve (suction valve)
Malfunction of bucket control
11
valve (LS shuttle valve)
Defective seal of check valve
12 of LS pressure sensing part
(control valve side)
Defective seal of travel
13
motor (safety valve)
Defective seal of travel
14
motor (check valve)
PC200, 200LC, 220, 220LC-8M0
Cause
a Be ready with engine stopped, then troubleshoot with engine
high idle.
Both sides in the NEUTRAL
a Be ready with engine stopped, then troubleshoot with engine
high idle.
Both sides in the NEUTRAL
Travel junction valve may malfunction. Check it.
Merge-divider main EPC valve may malfunction. Check it.
Merge-divider LS-EPC valve may malfunction. Check it.
Merge-divider main valve may malfunction. Check it.
Merge-divider LS valve may malfunction. Check it.
Spool of travel control valve may malfunction. Check it.
Pressure compensation valve of travel control valve may malfunc-
tion. Check it.
Suction valve of travel control valve may malfunction. Check it.
LS shuttle valve of bucket control valve may malfunction. Check it.
Seal of check valve of LS pressure sensing part (control valve
side) may be defective. Check it.
Seal of safety valve of travel motor may malfunction. Check it.
* Judgment can be made by checking a change of phenomenon
after exchanging safety valves between forward and reverse
circuit of the same motor or between right and left motor cir-
cuits.
Seal of check valve of travel motor may malfunction. Check it.
* You may replace the check valves of forward and reverse sec-
tions of the same motor or those of the right and left motors
with each other and judge from the change of the phenomenon.
Criteria and troubleshooting procedure
Travel lever
position
Either side operated
Travel lever
position
Either side operated
SEN06139-00
PPC valve output pressure
(Steering)
0 MPa
2
{0 kg/cm }
2.84 to 3.43 MPa
2
{29 to 35 kg/cm }
Travel junction solenoid valve
output pressure
0 MPa
2
{0 kg/cm }
Approx. 2.9 MPa
2
{Approx. 30 kg/cm }
40-500
29