Manitowoc National Crane NBT30H-2 Service Manual

2
National Crane 03-20-2019 Control # 613-06 2-9
NBT30H-2 SERVICE MANUAL HYDRAULIC SYSTEM
SERVICE
Hydraulic Oil Recommendations
For the hydraulic oil specifications, See “Lubrication” on
page 8-1.
Draining and Flushing
If a component has been changed because of a failure that
might allow metal or abrasive particles to enter the system,
all systems must be thoroughly checked, drained, and
flushed.
1. Remove the reservoir drain plug. Allow about three
minutes after hydraulic oil stops flowing from the drain
port for the side walls to drain.
2. Clean and install the reservoir plug and fill the reservoir
with a 50/50 mixture of fuel oil and clean hydraulic oil.
3. Cycle the crane through all functions several times.
Then return the crane to its stowed position and shut
down the engine.
4. Remove the reservoir drain plug and drain the reservoir.
Clean and install the drain plug and fill the reservoir with
clean hydraulic oil.
NOTE: Connect a drain hose in place of a disconnected
return line so that the hydraulic oil can be drained in
a container for proper disposal.
5. Disconnect the return line from the lift cylinder and raise
the boom to maximum elevation.
6. Connect the cylinder return line and lower the boom to
its stowed position. Replenish the reservoir hydraulic oil
level as required.
7. Disconnect the return line from an outrigger extension
cylinder and fully extend the outrigger.
O-RING FACE SEAL
O-RING BOSS
B
A
O-RING FACE
(REF)
O-RING BOSS
(REF)
A
B
O-RING FACE SEAL FITTING SIZE O-RING BOSS
THREAD
SIZE
B inches
(mm)
A inches
(mm)
TUBE
O. D.
MFGR
’S
SIZE
CODE
A inches
(mm)
B inches
(mm)
THREAD
SIZE
9/16-18 0.07 (1.78) 0.301 (7.64) 0.250 4 0.351 (8.92) 0.072 (1.83) 7/16-20
11/16-16 0.07 (1.78) 0.364 (9.24) 0.375 6 0.458 (11.63) 0.078 (1.98) 9/16-18
13/16-16 0.07 (1.78) 0.489(12.42) 0.500 8 0.644 (16.36) 0.087 (2.21) 3/4-16
1-14 0.07 (1.78) 0.614 (15.60) 0.625 10 0.755 (19.18) 0.097 (2.46) 7/8-14
1 3/16-12 0.07 (1.78) 0.739 (18.77) 0.750 12 0.924 (23.47) 0.116 (2.95) 1 1/16-12
1 7/16-12 0.07 (1.78) 0.926 (23.52) 1.000 16 1.171 (29.74) 0.116 (2.95) 1 5/16-12
1 11/16-12 0.07 (1.78)
1.176
(29.87)
1.250 20 1.475 (37.46) 0.118 (3.00) 1 5/8-12
2-12 0.07 (1.78)
1.489
(37.82)
1.500 24 1.720 (43.69) 0.118 (3.00) 1 7/8-12
NOTE:
Contact your National Crane Distributor or Manitowoc Crane Care for O-Ring boss seal kits.
CAUTION
Hydraulic oil supply lines must be connected to the
cylinders when flushing the system.

Manitowoc National Crane NBT30H-2 Specifications

General

Brand	Manitowoc
Model	National Crane NBT30H-2
Category	Construction Equipment
Language	English