When The Control Lever Is Switched From "Hold" To "Tilt," The Bucket Falls Temporarily; The Control Levers Of The Lift Arm And Bucket Do Not Move Smoothly And Heavy - Komatsu WA250-6 Shop Manual

500 Troubleshooting of hydraulic and mechanical system (H-mode)
H-25 When the control lever is switched from "HOLD" to "TILT," the bucket falls temporarily
H-25 When the control lever is switched from "HOLD" to "TILT," the
bucket falls temporarily
Check of Phenomenon
When the control lever is switched from "HOLD" to "TILT" gradually at low idle of the engine, the bucket
q
falls temporarily due to its own weight. When the control lever is completely set to "TILT," the bucket
returns to normal.
Cause
Improper adhesion of bucket spool check valve of the work equipment valve
q
H-26 The control levers of the lift arm and bucket do not move smoothly
and heavy
Check of Abnormality
Refer to the criterion value table and check if the lever operating efforts are large practically.
q
No.
Diagnosis
1 Becomes heavy in some places during operation regardless of oil pressure and oil temperature
2 Becomes heavy overall during operation regardless of oil pressure and oil temperature
WA250, 250PZ-6
SEN03849-00
1
1
Cause
PPC
valve
a
C
Remedy
E
Q
Q
25
40-500