Machine Deviates In One Direction - Komatsu Galeo PC800-8 Shop Manual

SEN00794-02
H-16 Machine deviates in one direction
Failure

• Machine deviates in one direction

phenomenon
Relative • Check that the travel speed is normal. (If it is abnormal, carry out the related troubleshooting.)
information • Carry out all the troubleshooting in working mode P.
Wrong adjustment of main
1
pump
Malfunction of travel PPC
2
valve
Malfunction of travel
3
control valve (spool)
Defective travel control
4
Possible causes
valve (body)
and standard
value in normal
state
Defective seal of center
5
swivel joint
6 Leakage in travel motor
7 Defective travel motor
8 Internal defect of final drive
24
Cause Standard value in normalcy and references for troubleshooting
See TESTING AND ADJUSTING, Testing and adjusting travel deviation.
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 body of the travel control valve may have a malfunction, check
it directly.
aPrepare with the engine stopped, then carry out troubleshooting with
the engine at high idle.
If seal is defective, the machine deviates as shown in Fig. 1.
aPrepare with the engine stopped, then carry out troubleshooting with
the engine at high idle.
Since the travel motor may be defective, 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.)
(1) Machine deviates in the same direction, regardless
of its travel direction
Travel lever
Full stroke
Travel lever
Relieved on one side
Travel lever
Relieved on one side
40 Troubleshooting
PPC valve output pressure
+0.8
2.9 MPa
–0.2
+8
{30 kg/cm 2 }
–2
Leakage from swivel joint
Max. 100 cc/min
Leakage from travel motor
Max. 40 l/min
PC800, 850-8