Travel Speed Is Low - Komatsu Galeo PC138US-8 Shop Manual

SEN02468-01
H-16 Travel speed is low
Trouble

• Travel speed is low.

Related
• Conduct the troubleshooting in working mode P.
information
Malfunction of self-pressure
1
reducing valve
Malfunction of travel PPC
2
valve
Malfunction of pump merge-
3
divider valve
Possible causes
and standard
value in normal
state
4 Malfunction of unload valve
Malfunction of pump merge-
5
divider valve
Malfunction of travel control
6
lever (spool)
Malfunction of travel control
7 lever (pressure compensa-
tion valve)
Malfunction of travel control
8
lever (suction valve)
9 Travel motor defective
10 Final drive defective
18
Cause Standard value in normal state/Remarks on troubleshooting
a
a
Forward or reverse position
Difference in above output
a
a
The pump merge-divider valve may have a malfunction. Check it
directly.
The spool of the travel control lever may have a malfunction.
Check it directly.
The pressure compensation valve of the travel control lever may
have a malfunction. Check it directly.
The suction valve of the travel control lever may have a malfunc-
tion. Check it directly.
a
The final drive may have a defect in it. Check it directly. (It may be
checked by abnormal sound, abnormal heating, metal chips in
drain oil, etc.)
Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
Control levers
All levers in NEUTRAL
Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
Travel lever
between both sides
Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
Travel lever
All levers in NEUTRAL
Position for travel only
(On either or both sides)
Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
Control levers
All levers in NEUTRAL
Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
Travel lever
Travel circuit relieved
40 Troubleshooting
Control circuit basic pressure
3.2 ± 0.5 MPa
{33 ± 5 kg/cm }
2
PPC valve output pressure
Above 2.7 MPa
{Above 28 kg/cm }
2
Below 0.4 MPa
{Below 4 kg/cm }
2
Solenoid valve output pressure
0 MPa {0 kg/cm }
2
2.84 – 3.43 MPa
{29 – 35 kg/cm }
2
Unload pressure
2.8 ± 1.0 MPa
{28 ± 10 kg/cm }
2
Leakage from travel motor
1.65 l/min
PC138US, USLC-8
1