WCM CTX8010 Operations & Parts Manual page 45

Symptom
Boom (bucket rod and
bucket) move to one
direction only.
Boom (bucket rod and
bucket) does not move.
Boom (bucket rod and
bucket) drops too quick
or the cylinder drops at a
certain height even it is
not operated due to dead
weight
Boom (bucket rod and
bucket) works
powerlessly
Boom (bucket rod and
bucket) moves even it is
not operated
Hot hydraulic oil
No action of rotation (no
Possible causes
The sealing component of central rotation
connector is aged and damaged.
The left and right crawlers are of different
tightening.
Main valve core is stuck or valve rod spring
breaks.
Boom valve rod is stuck or of low
overloaded pressure
Fuel supply pipe leaks, detached, O ring
damaged or pipe fitting is loose
Sandstone in main valve or the low pressure
chamber is connected to the high pressure
chamber
Low overloaded valve pressure
Serious internal leak of cylinder
Loose oil pipe fitting, damaged O ring
Serious internal leak of multiway valve or
sandstone inside it
Low overloaded pressure
Serious internal leak of oil cylinder
The main valve is disabled due to internal
leak.
Multiway valve core is stuck or serious
internal leak
Multiway valve rod spring breaks
Leak of working cylinder, or the working
device drops due to dead weight
Low pressure of overload overflow valve or
the spring breaks
Wrong grade of hydraulic oil for excavator
Hydraulic oil cooler surface is polluted by oil
and dirt, which blocks the air hole.
Low oil level of hydraulic oil tank
The hydraulic components such as motor,
main valve and oil cylinder or sealing
components are seriously worn and cause
internal leak, which increases the oil
temperature. Traveling rotation and working
device are delayed and powerless. The hot
temperature degrades the hydraulic oil. The
safety valve is of poor air tightness, which
leads to overflow.
Hydraulic oil pipe breaks
Change the damaged component
Change the sealing component, repair
the inner wall or groove of cylinder
Adjust to specified pressure. Change
41
How to solve
Change the sealing component
Adjust
Repair or change
Repair
Change
Adjust
or change the cylinder.
Change
Change
Adjust
Change the oil seal
Repair or change
Grind or change
Change
Change the oil seal
the spring if it is broken.
Change the hydraulic oil
Wash
Add enough hydraulic oil
Change the elements in time
Change