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11. Troubleshooting
Trouble
Control
Cause
Solution
Spreader arms move
slowly or jerkily when
activated
Are the hoses
connected
properly?
Air in the hydraulic
system
Deaerate pump
system
Does the pump
unit work?
Device doesn’t
perform at its given
power
Check the
hydraulic fl uid level
in the supplying
pump
Insuffi cient
hydraulic fl uid in
the pump
Top off hydraulic fl uid,
deaerate
Following release,
the star grip doesn’t
return to the central
position
Cover damaged
or star grip hard to
move?
Damage to the
torsion spring for
reset
Repair by an
authorized dealer, by
personnel specially
trained by HURST, or
by HURST itself
Soiled valve or
star grip
Defective valve
Other mechanical
damage (e. g. star
grip)
Hoses cannot be
coupled
Is a mono-coupling
mounted?
Pressure too high
(e.g. caused by
too-high ambient
temperature)
Set hydraulic pump
to pressureless
circulation
Pressurized
Relieve pump
Coupling defective Coupling needs to be
replaced immediately
only by use of mono-
coupling-system:
It is frequently not
possible to couple
hose assemblies
Control the
degree of viscosity
and application
temperature of
the used hydraulic
fl uid
Hydraulic fl uid
not adapted to
the application
situation
Hydraulic fl uid
must be replaced
(see chapter
“Recommended
Hydraulic fl uids”)
Coupling defective Coupling needs to be
replaced immediately
Hydraulic fl uid leak
on the hoses or the
fi xing-ins
Are the hoses
defective?
Leak, possible
damage
Replace hoses
Damages on the
surface of the
hydraulic hoses
Mechanical
damages or
contact with
aggressive agents
Replace hoses
Hydraulic fl uid leaks
on the piston rod
Defective rod seal Repair by an
authorized dealer, by
personnel specially
trained by HURST, or
by HURST itself
Damage to the
piston
