H-19 The Bucket Does Not Tilt Back - Komatsu WA250-6 Shop Manual

SEN03849-00

H-19 The bucket does not tilt back

Ask the operator about the following:
Has the bucket come not to work suddenly
q
o
Seizure or breakage of each equip-
ment
Did any abnormal noise occur at the
time (And where)?
Was there the phenomenon that the bucket
q
worked slowly?
o Wear of parts or deformation of
spring
Inspection before diagnosis
Is the stroke of the bucket and lift arm con-
q
trol levers appropriate?
No.
Diagnosis
The lift arm cannot operate and the bucket can-
1
not tilt back
The bucket can lift the machine but cannot tilt
2 back, or the lift arm operates but the bucket can-
not tilt back
The bucket can tilt back without load but cannot
3
in digging or scooping up
4 The hydraulic pump causes an abnormal noise
5 Large hydraulic drift of bucket cylinder
When the engine is at full throttle, the steering
6
operation is heavy and slow
22
40-500
500 Troubleshooting of hydraulic and mechanical system (H-mode)
Tank to Pump
a b c d
C E E
Remedy
E X X
Q Q Q
Q
Q
Q Q
Q
Q Q
H-19 The bucket does not tilt back
Cause
Priority HST PPC Work equip-
valve pump valve ment valve
e f g
E E
X X X
Q Q
Q
1
Cylin-
der
h i j
A
X X X
Q Q
Q Q
Q
Q Q
WA250, 250PZ-6