Rotary valve rod on main valve is stuck.
The rotation support is damaged.
Indifferent left and right
rotation speed (no other
abnormalities)
The right and left rotation of multiway valve
is of different overloaded pressure
Rotation valve rod of multiway valve is
Delayed or powered
rotation (no other
abnormalities)
Serious external leak of hydraulic oil pipe
Change pipe fitting and sealing
components
Low overloaded pressure for rotation of
multiway valve
Serious internal leak of rotary motor
The high and low pressure chambers of
multiway valve are connected, sand hole on
valve body due to casting, which causes
one-way action or linked actions
The rotation mechanism
moves even it is operated
Main valve rod spring breaks
The excavator makes
abnormal noise and
shakes during operation.
Low oil level of hydraulic oil tank
The oil contains too much moisture and air
Safety valve of multiway valve makes noise
Vibration caused by loose pipe clamp
Air exists in oil suction hose
The bearing of working device is not
lubricated or scraped
Apply lubrication oil or change the
shaft or sleeve
Powerless oil cylinder or
oil leak
Damaged sealing components
Change the sealing components
A groove is found on the piston rod due to
abrasion or detachment of chromium coating
of piston rod, which causes oil leak.
Coat, paint, repair or change
The air in the cylinder causes shaking noise
during operation
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