5
CAUTION
DO NOT OVERFILL! With ram
fully retracted and jack in upright position, oil level
should not be higher than shown in Fig. 5 or Fig. 6
(as applicable for your jack model).
5. Reinstall oil fill/air release plug.
6. Bleed air as described in Section 6.2.
6.2 Air Bleeding
The following procedure should be performed after
adding oil and whenever a “spongy” feel is noticed
during jack operation.
To remove air from the jack:
1. Using end of pump handle, turn the release valve
stem counter-clockwise to open valve (do not turn
more than two revolutions).
2.
Insert pump handle into handle socket. Operate
handle 6 to 8 strokes.
3. Using end of pump handle, turn the release valve stem
clockwise until valve is fully closed.
4.
Insert pump handle into handle socket. Operate
handle until ram is fully extended.
5. Operate pump handle an additional 5 to 6 strokes.
6. Using end of pump handle, turn the release valve
stem counter-clockwise to open valve (do not turn
more than two revolutions).
7. Push the ram all the way down until it is fully retracted.
8. Using end of pump handle, turn the release valve
stem clockwise until valve is fully closed.
9. All models except GBJ100: Using fingers, push the
rubber oil fill/air release plug to the side to release
any trapped air.
10. Model GBJ100 only: Loosen oil fill/air release plug
1 to 2 turns to release any trapped air. Tighten plug
after releasing air.
6.3 Inspection
Visually inspect the jack before each use. Remove the
jack from service immediately and take corrective action
if any of the following problems are found:
a. Cracked or damaged housing.
b. Excessive wear, bending or other damage.
c. Leaking hydraulic fluid.
d. Scored or damaged piston rod (ram).
e. Incorrectly functioning extension screw.
f. Loose hardware.
g. Modified or altered equipment.
If the jack appears damaged in
any way and/or shows signs of malfunctioning, it
must be immediately removed from service. The jack
must remain out of service until it has been inspected
and repaired by an Enerpac Authorized Service
Center or other qualified
hydraulic service facility.
6.4 Periodic Maintenance
Thoroughly lubricate all pivot pins and linkages with
lubricating oil before using the jack and after every 10
ram up/down cycles. See Fig. 7.
Fig. 7 - Lubrication
OIL
Periodically check the ram for signs of corrosion. Clean
as needed and wipe with an oil saturated cloth.
7.0 STORAGE
Before storing the jack:
• Push the ram all the way down, so that it is fully
retracted and protected from damage and corrosion.
• Be sure that extension screw (if equipped) is turned
all the way down to protect the threads from damage.
• Wipe off any dirt or oil.
• Be sure that the release valve is fully closed.
Always store the jack in the upright position, in a
protected location where it will not be exposed to
corrosive vapors, abrasive dust or any other harmful
elements.
8.0 TRANSPORTING AND POSITIONING THE JACK
• Models GBJ002A through GBJ050A: These models
can be transported and positioned by hand, without use
of an auxiliary lifting device. For added convenience,
a positioning handle is provided on models GBJ020A,
GBJ020SA, GBJ030A and GBJ050A.
• Model GBJ-100: This model must be transported and
positioned using a hoist or other auxiliary lifting device
of appropriate capacity. Attach the lifting device hook
to the jack positioning handle.
Models GBJ020A through GBJ100: Refer to
Fig. 1 for location of jack positioning h
andle (item #11).
Summary of Contents for GBJ Series
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