JLG 680S, Service And Maintenance Manual

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SECTION 2 - GENERAL
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Component Disassembly and Reassembly
When disassembling or reassembling a component, complete
the procedural steps in sequence. Do not partially disassemble
or assemble one part, then start on another. Always recheck
your work to assure that nothing has been overlooked. Do not
make any adjustments, other than those recommended, with-
out obtaining proper approval.
Pressure-Fit Parts
When assembling pressure-fit parts, use a molybdenum disul-
fide base compound or equivalent to lubricate the mating sur-
face.
Bearings
1. When a bearing is removed, cover it to keep out dirt and
abrasives. Clean bearings in nonflammable cleaning sol-
vent and allow to drip dry. Compressed air can be used
but do not spin the bearing.
2. Discard bearings if the races and balls (or rollers) are pit-
ted, scored, or burned.
3. If bearing is found to be serviceable, apply a light coat of
oil and wrap it in clean (waxed) paper. Do not unwrap
reusable or new bearings until they are ready to install.
4. Lubricate new or used serviceable bearings before
installation. When pressing a bearing into a retainer or
bore, apply pressure to the outer race. If the bearing is to
be installed on a shaft, apply pressure to the inner race.
Gaskets
Check that holes in gaskets align with openings in the mating
parts. If it becomes necessary to hand-fabricate a gasket, use
gasket material or stock of equivalent material and thickness.
Be sure to cut holes in the right location, as blank gaskets can
cause serious system damage.
Bolt Usage and Torque Application
SELF LOCKING FASTENERS, SUCH AS NYLON INSERT AND THREAD DEFORMING
LOCKNUTS, ARE NOT INTENDED TO BE REINSTALLED AFTER REMOVAL.
1. Always use new replacement hardware when installing
locking fasteners. Use bolts of proper length. A bolt
which is too long will bottom before the head is tight
against its related part. If a bolt is too short, there will
not be enough thread area to engage and hold the part
properly. When replacing bolts, use only those having
the same specifications of the original, or one which is
equivalent.
2. Unless specific torque requirements are given within the
text, standard torque values should be used on heat-
treated bolts, studs, and steel nuts, in accordance with
recommended shop practices. (See Torque Chart Sec-
tion 1.)
Hydraulic Lines and Electrical Wiring
Clearly mark or tag hydraulic lines and electrical wiring, as well
as their receptacles, when disconnecting or removing them
from the unit. This will assure that they are correctly rein-
stalled.
Hydraulic System
1. Keep the system clean. If evidence of metal or rubber
particles are found in the hydraulic system, drain and
flush the entire system.
2. Disassemble and reassemble parts on clean work sur-
face. Clean all metal parts with non-flammable cleaning
solvent. Lubricate components, as required, to aid
assembly.