Lift Cylinders; How To Remove The Lift Cylinder - Gs-3390, Gs-4390 - Terex GS90D-4695 Service And Repair Manual

December 2023
3-5

Lift Cylinders

The lift cylinders are double acting hydraulic
cylinders. The GS-3390 and GS-4390 use one lift
cylinder; the GS-5390 uses two. Each lift cylinder
is equipped with a counterbalance valve to prevent
movement in the event of a hydraulic line failure.
How to Remove the Lift Cylinder -
How to R emove the Lift Cylinder - GS-3390, GS-4390
GS-3390, GS-4390
Bodily injury hazard. The
counterbalance valve in the lift
cylinder is factory set. Do not
attempt to adjust the
counterbalance valve.
Attempting to adjust the
counterbalance valve could
result in death or serious injury
and significant component
damage. Dealer service is
strongly recommended.
Bodily injury hazard. This
procedure requires specific repair
skills, lifting equipment and a
suitable workshop. Attempting
this procedure without these
skills and tools could result in
death or serious injury and
significant component damage.
Dealer service is strongly
recommended.
Note: When removing a hose assembly or fitting,
the O-ring (if equipped) on the fitting and/or hose
end must be replaced. All connections must be
torqued to specification during installation. Refer to
Specifications, Hydraulic Hose and Fitting Torque
Specifications.
Part No. 1325652GT
1
2
Note: Be sure that the safety arm is locked in the
vertical position.
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4
5
GS -3390 • GS -4390 • GS
™ ™
Service and Repair Manual
Scissor Components
Start the engine from the ground controls and
raise the platform approximately 18 feet /
5.5 m from the ground.
Release the safety arm latch, lift the safety
arm and rotate to a vertical position. Lock the
safety arm in position.
Lower the platform onto the safety arm. Turn
the machine off.
Crushing hazard. Keep hands
clear of the safety arm when
lowering the platform.
Component damage hazard.
The link set cross tube can be
damaged if excessive force is
applied. Do not continue to
lower the platform after the
safety arm makes contact with
the cross tube.
Support the platform using a 5 ton / 5000 kg
overhead crane. Do not apply lifting pressure
at this time.
Tag, disconnect and plug the hydraulic hoses
from the lift cylinder. Cap the fittings on the
cylinder.
Bodily injury hazard. This
procedure requires specific repair
skills, lifting equipment and a
suitable workshop. Attempting
this procedure without these
skills and tools could result in
death or serious injury and
significant component damage.
Dealer service is strongly
recommended.
-5390
™
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