JLG 4017PS Service Manual - Manual (Page 79)

3-41 3706PS, 3707PS, 4014PS, 4017PS, 33.7, 37.6, 37.7
Boom
6. Start the engine and SLOWLY lower the boom until
there is a clearance of 6 mm (0.25 in) between the
end of the boom prop and the lift/lower cylinder rod
end (3).
7. Shut OFF engine.
b. Prop Removal
1. If needed, start machine and slowly raise the boom
until the boom prop is clear of the lift/lower rod end.
2. Remove the o-rings (2) and boom prop (1) from the
cylinder. Return the boom prop to the proper location
and secure.
3. Lower boom, shut engine OFF.
3.21 EMERGENCY BOOM LOWERING
PROCEDURE
3.21.1 Equipment and Supplies Required
Auxiliary Hydraulic Power Supply:
• Portable hydraulic unit or another machine with
an auxiliary hydraulic power supply with a capac-
ity to hold up to 35 L (9 gal) of hydraulic oil from
the machine during lowering process.
Hoses:
• Two Hydraulic Hoses - Approximately 3,0 m
(10 ft) each, with a minimum I.D. of
9,5 mm (0.375 in) and a minimum rating of
275,8 bar (4000 psi).
Fittings:
• Two -8 ORFS Caps
• Two -8 ORFS Plugs
Adaptors:
• Two -8 ORFS Adaptors
Note: Machine extend/retract and lift/lower hoses are -8
ORFS. The adaptor size may vary depending on the
hose ends of the auxiliary hydraulic power supply.
NOTICE
EQUIPMENT DAMAGE. DO NOT operate with the
boom prop in place. Damage to the boom prop and/or
the lift/lower cylinder could occur.
WARNING
To avoid instability of the machine, the extend/retract
cylinder MUST BE fully retracted prior to retracting
the lift cylinder. If circumstances prevent retraction of
the extend/retract cylinder first, lower the lift cylinder
the minimum amount necessary and resume
retraction of the extend/retract cylinder as soon as
possible.
NOTICE
EQUIPMENT DAMAGE. Auxiliary Hydraulic Power
Supply hydraulic oil must be compatible with
hydraulic oil shown in Section , “.”