Accessory System Checks And Adjustments; High Pressure Accessory Systems; Low Pressure Accessory Manifold - Manitowoc 999 Service And Maintenance Manual

HYDRAULIC SYSTEM

Accessory System Checks and Adjustments

High Pressure Accessory Systems

The high-pressure side of the rear drum system is the source
for upper and lower accessory systems. The high-pressure
upper accessory system includes mast assist cylinders,
gantry cylinders, and boom pin pusher cylinder. The high-
pressure lower accessory system includes crawler pin
pusher cylinders and carbody jack cylinders.
For mast, gantry, and boom pin cylinders select and confirm
Setup mode.
1. Mast cylinders:
a. Mast bypass valve
o n p o s i t i o n d u r i n g c r a n e a s s e m b l y a n d
disassembly.
b. Press top and bottom of mast control to raise and
lower mast cylinders several times to remove air
from system.
c. Scroll to accessory screen on diagnostic display to
verify that 3,000 psi (207 bar) is present when
cylinders are extended.
d. Mast bypass valve
off position during normal crane operation.
CAUTION
Damage to Gantry!
When raising gantry for first time or after maintenance of
gantry cylinder, raise gantry slowly and check that both
cylinders are raising gantry evenly. Gantry could twist if
one cylinder is not working correctly.
2. Gantry cylinders:
a. Access setup remote control in left side enclosure.
2-26
(Figure 2-22) must be turned to
(Figure 2-22) must be turned to
OFF
ON
View in Right Side Enclosure
FIGURE 2-22
Published 05-16-17, Control # 233-03
999 SERVICE/MAINTENANCE MANUAL
b. Use gantry toggle to raise and lower gantry several
times to remove air from system.
c. Scroll to accessory screen on diagnostic display to
verify that 3,000 psi (241 bar) is present when
gantry is extended.
3. Boom pin pusher cylinder:
a. Access setup remote control in left side enclosure.
b. Use boom hinge pins switch on remote control to
engage and disengage cylinders several times to
remove air from system.
c. Verify that 3,000 psi (241 bar) is present when
cylinder is extended.
4. Crawler pin pusher cylinder:
a. With handle on lower accessory valve, engage and
disengage both crawler pin pusher cylinders
several times to remove air from system.
b. Verify that 3,000 psi (241 bar) is present when
cylinder is extended.
5. Carbody valves (Figure
a. With handle on lower accessory valve, fully retract
the carbody jacks if they are not already retracted.
b. Extend carbody jacks to full extend position.
c. Verify that 3,000 psi (241 bar) is present when each
jack is extended.
d. When retracting jacks, the carbody must lower
slowly and smoothly.
Rear Right
Right Crawler
Jack Pins
Front
Right
Jack
Front of Carbody

Low Pressure Accessory Manifold

The rear drum charge pump is the low-pressure source for
the accessory manifold, at a pressure of 350 psi (24 bar).
T h e l o w - p r e s s u r e s y s t e m i n c l u d e s d r u m p a w l s ,
2-23):
Left Rear
Crawler Left
Pins Jack
Front
P1476
FIGURE 2-23
Left
Jack