Machine Does Not Travel (Only One Track) - Komatsu Galeo PC800-8 Shop Manual

SEN00794-02
H-20 Machine does not travel (only one track)
Failure

• Machine does not travel (only one track)

phenomenon
Relative
information
Malfunction of travel motor
1
(parking brake)
Possible causes
and standard
Internal defect of travel
2
value in normal
motor (body)
state
3 Internal defect of final drive
Failure
• Machine does not travel (only one track)
phenomenon
Relative
• Carry out all the troubleshooting in working mode P.
information
Malfunction of travel PPC
1
valve
Malfunction of travel
2
control valve (spool)
Possible causes
and standard
Defective travel control
3
value in normal
valve (suction valve)
state
Malfunction of travel motor
4
(safety valve)
Malfunction of travel motor
5
(counterbalance valve)
28
Cause Standard value in normalcy and references for troubleshooting
Since the parking brake of the travel motor may have a malfunction,
check it directly.
Since the travel motor may have a defect in it, check it directly.
Since the final drive may have a defect in it, check it directly. (The defect
can be judged by abnormal sound, abnormal heat, metal chips in
drained oil, etc.)
Cause Standard value in normalcy and references for troubleshooting
aPrepare with the engine stopped, then carry out troubleshooting with
the engine at high idle.
FORWARD, REVERSE
Since the spool of the travel control valve may have a malfunction,
check it directly.
Since the suction valve of the travel control valve may have a malfunc-
tion, check it directly. (The suction valve can be checked by replacing it
with normal one.)
aPrepare with the engine stopped, then carry out troubleshooting with
the engine at high idle.
(Direction in which machine does not
Since the counterbalance valve of the travel motor may have a malfunc-
tion, check it directly.
(1) Machine does not travel in either direction.
(2) Machine does not travel forward or in reverse
Travel levers
Full stroke
Travel levers
Relieved on one side
travel)
40 Troubleshooting
PPC valve output pressure
+0.8
2.9 MPa
–0.2
+8
{30 kg/cm 2 }
–2
Travel relief pressure
+1.0
34.8 MPa
–2.0
+10
{355 kg/cm 2 }
–20
PC800, 850-8