2
National Crane
03-20-2019 Control # 613-06
2-5
NBT30H-2 SERVICE MANUAL
HYDRAULIC SYSTEM
MAINTENANCE
Preparation
Before maintenance, adjustments and repairs are started on
a crane, the following precautions shall be taken as
applicable:
NOTE:
Maintenance, adjustments and repairs shall be
done only by designated personnel who are
properly trained. Use only Manitowoc supplied
parts to repair the crane.
•
Place a warning tag in a conspicuous location at the
controls stating that the machine requires adjustment or
repair before it can be operated.
•
Park the crane where it will cause the least interference
with other equipment or operations in the area.
•
Place all controls at the off position and set the brakes to
prevent inadvertent motion.
•
Disable all methods used to start the truck's engine.
•
Lower the boom to the ground or otherwise secure
against dropping.
•
Lower the hook block to ground or otherwise secure
against dropping.
•
Relieve the hydraulic pressure from all hydraulic circuits
before loosening or removing hydraulic components.
After maintenance, adjustments and repairs have been
made, do not return the crane to service until all guards have
been reinstalled, trapped air removed from the hydraulic
system if required, safety devices reactivated, and
maintenance equipment and all warning tags removed.
Maintenance, adjustments and repairs shall be done only by
designated personnel who are properly trained. Use only
Manitowoc supplied parts to repair the crane.
Hydraulic System Maintenance Precautions
Contaminants in a hydraulic system affect operation and
result in serious damage to the system components. Dirty
hydraulic systems are a major cause of component failures.
If evidence of foreign particles is found in the hydraulic
system, flush the system.
Disassemble and reassemble hydraulic components on a
clean surface.
Clean all metal parts in a nonflammable cleaning fluid. Then
lubricate all components to aid in assembly.
Inspect all sealing elements (O-ring, gaskets, etc.) when
disassembling and assembling the hydraulic system
components. Installation of new sealing elements is always
recommended.
When installing metal hydraulic tubes, tighten all bolts finger
tight. Then, in order, tighten the bolts at the rigid end, the
adjustable end, and the mounting brackets. After tubes are
mounted, install the hoses. Connect both ends of the hose
with all bolts finger tight. Position hoses so they do not rub
the machine or another hose and has a minimum of bending
and twisting. Tighten bolts in both couplings.
Due to manufacturing methods, there is a natural curvature
to a hydraulic hose. The hose should be installed so any
bend is with this curvature.
In case of replacement hoses with angled stem reusable
fittings, the hose curvature must be taken into consideration
when assembling and positioning the angled stem.
Label Parts when Disassembling
When removing or disconnecting a group of wires or cables,
tag each one to ensure proper identification during re-
assembly.
When shims are removed, tie them together and identify
them as to location. Keep shims clean and flat until they are
reinstalled.
Hydraulic Oil Recommendations
For the hydraulic oil specifications, refer to
Parts Replacement
Parts found damaged or out of tolerance when maintenance
is being performed should be replaced. Refer to the Parts
Catalog for proper replacement parts.
Visual Inspection of Hoses and Fittings
1.
Visually inspect hoses and fittings once a month or
every 250 hours for the following:
-
Leaks at hose fitting or in hose
-
Damaged, cut or abraded cover
-
Exposed reinforcement
-
Kinked, crushed flattened, or twisted hose
-
Hard, stiff, heat cracked, or charred hose
-
Blistered, soft, degraded, or loose cover
-
Cracked, damaged, or badly corroded fittings
-
Fitting slippage on hose
-
Other signs of significant deterioration
If any of the above conditions exist, evaluate hose
assemblies for correction or replacement. For replacement
of hose assemblies, refer to your Parts Manual.
Содержание National Crane NBT30H-2
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Страница 40: ...1 30 03 20 2019 Control 613 06 INTRODUCTION NBT30H 2 SERVICE MANUAL ...
Страница 92: ...ELECTRIC SYSTEM NBT30H 2 SERVICE MANUAL 3 24 03 20 2019 Control 613 06 ...
Страница 110: ...BOOM MAINTENANCE NBT30H 2 SERVICE MANUAL 4 18 03 20 2019 Control 613 06 ...
Страница 132: ...SWING NBT30H 2 SERVICE MANUAL 6 14 03 20 2019 Control 613 06 ...
Страница 142: ...OUTRIGGERS NBT30H 2 SERVICE MANUAL 7 10 03 20 2019 Control 613 06 ...
Страница 158: ...LUBRICATION NBT30H 2 SERVICE MANUAL 8 16 03 20 2019 Control 613 06 ...
Страница 190: ...SCHEMATICS NBT30H 2 SERVICE MANUAL 10 2 ...
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