MAINTENANCE CHECKLIST
OPERATOR MANUAL
NBT60XL
6-6
Published 11-01-2020 Control # 710-00
operating sheave or snatch block is essential to safety and
long service life of the rope.
Do not use worn sheaves or sheaves with flat grooves
because they do not provide sufficient support to prevent the
distortion and flattening of the rope. Sheaves with nicked or
broken flanges can cut or otherwise damage the rope.
An even distribution of rope coils over the hoist drum is
essential to smooth operation. This prevents the rope from
cutting down through or crushing other coils on the drum
resulting in damage to and difficulty in unwinding the rope.
REPLACEMENT ROPE
If the hoist rope needs to be replaced, care should be taken
in selecting a suitable replacement rope. The rope strength
requirements are shown on the crane load chart. The types
of rope are optional with 6 × 25 and Dyform being the most
common. A high strength, rotation resistant rope is preferred
and is furnished as standard by National Cranes. This rope
eliminates single part line load spin and prolongs rope life. It
also eliminates load block spin up when multi-part reeving is
used. For more information, see “Specifications” on page 6-
10.
CRANE ADJUSTMENTS AND REPAIRS
Before adjustments and repairs are started on a crane, read
and be familiar with the safety information outlined under
“Maintenance” on page 2-26.
Boom Extension Cable
If a cable replacement is required for the boom extension
system, the replacement cable must be obtained through the
Manitowoc Crane Care. Extension cables are pre-stretched
and have special connections for proper operation.
NOTE:
National Crane recommends that boom extension
cables be replaced every seven (7) years.
Jib Jack Service and Maintenance
Important: Use only a good grade hydraulic jack oil,
transmission oil, or turbine oil. Avoid mixing types of oil. Do
not use brake fluid, alcohol, glycerin, detergent motor oil, or
dirty oil. Improper fluid can cause serious internal damage to
the jack rendering it inoperative.
Adding Oil to the Jib Jack
To add oil to the jib jack, do the following:
1.
Set the jack in an upright level position.
2.
Lower the saddle and make sure the piston is fully
depressed.
3.
Remove the oil filler plug.
4.
Fill until the oil is level with the filler plug hole.
Changing the Jib Jack Oil
For best performance and longest life, replace the oil at least
once a year. To change oil, do the following:
1.
Remove the filler plug.
2.
Lay the jack on its side and drain the oil into a suitable
drain pan. The oil will run slowly because air must enter
as oil drains out.
3.
Be careful to prevent dirt or foreign matter from entering
the system.
4.
Replace with proper oil as described above.
Lubrication
Add proper lubrication oil to all pivoting sections every three
months.
Rust Prevention
Check the ram every three months for any sign of rust or
corrosion. Clean as needed and wipe with an oil saturated
cloth.
NOTE:
When not in use, always leave the saddle and ram
all the way down.
HYDRAULIC SYSTEM
Oil Cooler
The heat exchanger must be kept clean for efficient
operation of the hydraulic cooler system. Wash the heat
exchanger core frequently to eliminate oil film, road dirt, and
other foreign object buildup on the heat exchanger fins.
Frequent inspection and tightening of hose clamp eliminates
the possibility of end connection failure due to back pressure
from a cold startup.
If the cooler system fails to provide adequate performance,
reduced air or oil flow through the heat exchanger is the
probable cause. Inspect the cooling fan for proper operation.
Any obstructions to air flow should be corrected (cooler too
close to other truck components, foreign matter in heat
exchanger fins, etc.) All hydraulic lines should be periodically
checked for obstructions, hose kinks, or other flow
restrictions.
Fo
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