29
MAN 9064762 EN V1
P. Lindberg A/S
Sdr. Ringvej 1
www.p-lindberg.dk
Tel.: 70212626
DK-6600 Vejen
e-mail: salg@p-lindberg.dk
The hydraulic system
Symptom
Possible cause
Solution
Boom (bucket arm and
bucket) does not move.
The boom valve stem is stuck
or has low overload pressure.
Repair.
The fuel pipe is leaking, is torn
off, the O-ring is damaged or
the pipe fitting is loose.
Replace the damaged
component.
Dirt in the main valve.
Replace.
Boom (bucket arm and
bucket) falls too quickly or
the cylinder falls at a
certain height even though
it is not operated, due to
own weight.
Low overload pressure in the
valve.
Adjust.
Internal leak in the cylinder.
Replace the gaskets or
cylinder.
Hot hydraulic oil.
Incorrect quality of hydraulic
oil for the excavator.
Change the hydraulic oil.
The hydraulic cooler surface is
contaminated with oil and
dirt, which is blocking the air
hole.
Clean.
Low oil level in the hydraulic
oil tank.
Add sufficient hydraulic oil.
Operating rotation and
workpiece are lowered and
weak.
The hydraulic components,
engine, main valve, oil cylinder
or seal components are very
worn and causing internal
leakage, which increases the
oil temperature. The warm
temperature breaks down the
hydraulic oil. The safety valve
is not air tight, which is
causing overflow.
Replace the elements
promptly.
Unequal rotation speed (no
other abnormalities).
Right rotation and left rotation
of the multidirectional valve
have different overload
pressures.
Adjust.
Rotation valve stem on main
valve is stuck.
Adjust the screws on the top
and bottom of the valves.
No rotation or rotates a
little on its own.
Exterior leakage in the
hydraulic oil pipe.
Replace the pipe fitting and
sealing components.
Low overpressure pressure
for rotation of multidirectional
valve.
Adjust.
