Travel Speed Is Low - Komatsu PC200-8M0 Shop Manual

SEN06139-00
H-18 Travel speed is low
q
Failure

Travel speed is low.

Related infor-
q
Perform all troubleshooting with working mode in power mode (P).
mation
Malfunction of travel PPC
1
valve
Malfunction of self-pressure
2
reducing valve
3 Malfunction of LS-EPC valve
Probable
causes and cri-
teria
Malfunction of travel control
4
valve (spool)
Malfunction of travel control
5 valve (pressure compensa-
tion valve)
Malfunction of travel control
6
valve (suction valve)
Malfunction of bucket control
7
valve (LS shuttle valve)
8 Defective travel motor
9 Defective final drive
28
40-500
500 Troubleshooting of hydraulic and mechanical system (H-mode)
Cause
a Be ready with engine stopped, then troubleshoot with engine
high idle.
a Be ready with engine stopped, then troubleshoot with engine
high idle.
All levers in the neutral position
a Be ready with engine stopped, then troubleshoot with engine
high idle.
Travel speed
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 have malfunction.
Check it.
a Be ready with engine stopped, then troubleshoot with engine
high idle.
Final drive may have internal defect. Check it.
* It may be checked by abnormal sound, abnormal heating,metal
chips in drain oil, etc.
Criteria and troubleshooting procedure
Travel lever
Neutral
Forward
Reverse
Control lever
Travel lever
Lo Neutral
Hi Operation
Travel lever
Travel system relief
PC200, 200LC, 220, 220LC-8M0
H-18 Travel speed is low
PPC valve output pressure
0 MPa
2
{0 kg/cm }
2.84 to 3.43 MPa
2
{29 to 35 kg/cm }
Control circuit source pressure
2.84 to 3.43 MPa
2
{29 to 35 kg/cm }
LS-EPC valve
output pressure
Approx. 2.9 MPa
{Approx. 30 kg/cm
0 MPa
2
{0 kg/cm }
Leakage from travel motor
27.2 l/min
2
}