Travel Speed Does Not Change Or It Is Kept Low Or High; Track Does Not Move (Only Either Side) - Komatsu PC130-8 Shop Manual

40 Troubleshooting
H-19 Travel speed does not change or it is kept low or high
Trouble

• Travel speed does not change or it is kept low or high.

Related
• Conduct the troubleshooting in working mode P.
information
Possible causes
Malfunction of travel speed
and standard 1
selector solenoid valve
value in normal
state
Malfunction of travel motor
2
(speed-changer unit)
H-20 Track does not move (Only either side)
Trouble

• Track does not move (only either side).

Related
• Conduct the troubleshooting in working mode P.
information
Defective seat of travel con-
1
trol valve (suction valve)
Defective seat of travel con-
2 trol valve (safety and check
valve)
Possible causes
Malfunction of travel motor
3
and standard
(counterbalance valve)
value in normal
state
4 Travel motor defective
5 Final drive defective
PC130-8
Cause
a
The speed-changer unit of the travel motor may have a malfunc-
tion. Check it directly.
Cause
The suction valve seat of the travel control lever may be defective.
Check it directly.
The safety and check valve seat of the travel control lever may be
defective. Check it directly.
The counterbalance valve of the travel motor 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.)
Standard value in normal state/Remarks on troubleshooting
Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
Travel speed Travel lever
Lo In NEUTRAL
Hi
Standard value in normal state/Remarks on troubleshooting
Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
Travel lever
Travel circuit relieved
SEN04124-00
Solenoid valve output
pressure
0 MPa {0 kg/cm
2.84 – 3.43 MPa
Operated
{29 – 35 kg/cm
Leakage from travel motor
Below 1.7 l/min
1
}
2
}
2
1
21