Manitowoc National Crane NBT40-1 Series User Manual

National Crane 3-29-2018 Control # 610-00 8-9
NBT40-1 SERIES OPERATOR MANUAL MAINTENANCE CHECKLIST
8
System is in a state of
constant cut-out.
Blown fuse.
Check fuse at equipment cab console. Replace
if necessary.
ATB switch open. Ensure that ATB switch is closed.
System cuts out too early or
too late.
RCL programmed wrong. Reprogram RCL with correct lift values.
Jib Jack Troubleshooting
Will not lift load.
No oil in system.
Release valve not closed.
Add oil to reservoir.
Turn handle clockwise tightly.
Will lift load only part way. Oil level low. Add oil to reservoir tank.
Will lift load but will not
hold.
The following valve or valves leaking.
a. Suction valve
b. Delivery valve
c. Release valve
Replace jack
Packings worn or damaged. Replace jack
Jack will not lower.
Release valve stuck, probably dirt or
foreign matter.
Transfer load then replace dirty oil, flush oil
reservoir with non-flammable solvent.
Poor lifting.
Dirty oil.
Air in hydraulic system.
Change oil.
Purge air from system.
Poor pumping action.
Oil seal for pump unit worn in out or
damaged.
Replace jack.
Condition Possible Cause Possible Solution

Manitowoc National Crane NBT40-1 Series Specifications

General

Brand	Manitowoc
Model	National Crane NBT40-1 Series
Category	Construction Equipment
Language	English