9.1 GENERAL TROUBLESHOOTING
This troubleshooting information covers the components and systems as described in this MANUAL.
Should in depth troubleshooting, repair or replacement of components or adjustment of valves be
required, contact an authorized dealer/distributor for assistance.
SYS
TROUBLE DESCRIPTION
PROBABLE CAUSE
POSSIBLE REMEDY
G
NI
TA
RE
P
O
1. All operating speeds
are slow or power is
lost.
a. Low hydraulic oil level
Fill oil to specified level
b. Air leaking into the suction pipe
Tighten suction pipe
hose clamp or replace
hose
c. Hydraulic pump is damaged
Repair or replace
d. Pilot gear pump is damaged
Repair or replace
e. Main relief valve is not adjusted correctly
Adjust or replace
f. Pilot relief valve is not adjusted correctly
Adjust or replace
2. A specific cylinder func-
tions improperly or los-
es power.
a. Cylinder seal is damaged
Repair or replace
b. Control valve or overload relief valve functions incor-
rectly or there are signs of air in the cylinder
Repair or replace/Re-
move air from cylinder
c. Pilot valve is damaged
Repair or replace
d. Pilot valve piping is loose
Retighten
3. The cylinder position
will not hold with operat-
ing lever in neutral.
a. Cylinder seal is scored
Repair or replace
b. Control valve or overload relief valve is damaged
Repair or replace
c. Pilot valve is damaged
Repair or replace
4. Machine does not slew. a. Hydraulic motor (slewing) is not working or slewing
gear is damaged
Repair or replace
b. Slewing bearing is damaged
Repair or replace
c. Pilot valve is not working
Repair or replace
d. Slewing reduction unit is damaged
Repair or replace
e. Solenoid valve is not working
Repair or replace
f. Control valve is not working
Repair or replace
g. Lever lock Solenoid valve is not working
Repair or replace
5. Slewing speed is slow.
a. Control valve is not working
Repair or replace
b. Hydraulic motor (slewing) is not working
Repair or replace
c. Hydraulic pump is not working
Repair or replace
d. Pilot valve is not working
Repair or replace
6. Abnormal sound occurs
when slewing.
a. Insufficient lubrication of slewing gear and bearings Grease
b. Pilot valve is not working
Repair or replace
c. Control valve is not working
Repair or replace
LE
V
A
RT
1. Machine does not travel
smoothly.
a. Too much crawler tension
Adjust crawler tension
b.
D
irty or clogged crawler belts/shoes
Clean crawlers
c.
B
rake valve is not working
Repair or replace
d. Travel reduction unit is damaged
Repair or replace
e. Control valve is not working
Repair or replace
f. Travel motor damaged
Repair or replace
g. Main relief valve pressure is set incorrectly
Adjust or replace
h. Swivel joint is damaged
Repair or replace
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9. TROUBLESHOOTING
]
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