Manitowoc 999 Service And Maintenance Manual

Reference Only
Manitowoc Published 05-16-17, Control # 233-03 1-61
999 SERVICE/MAINTENANCE MANUAL INTRODUCTION
1
Left and Right Crawler Pin-Pusher Cylinders
Crawler pin pusher cylinder operation is controlled with
hydraulic valve handles on the carbody and PC
programming. The following description of operation is for
right side set of crawler pin pusher cylinders. Operation of
both sets of pin cylinders is the same.
Right Crawler Pin-Pusher Cylinders Engage
See Figure 1-44
Move right crawler pins lever (1) back to engage position to
extend crawler pin pusher cylinders (2) into crawler track
frame. This shifts selected carbody lower accessory valve to
block charge pressure to accessory pressure switch (4).
The accessory pressure switch trips when the system
pressure drops to 120 psi (8,3 bar), sending an input signal
to the PC. The PC sends a negative output voltage to rear
drum pump EDC that tilts rear drum pump swashplate to
stroke pump (3) in the low-pressure side direction. Low-
pressure side hydraulic fluid flows through the high-pressure
carry-over of accessory system valve where the system
pressure is 3,000 psi (207 bar). Hydraulic fluid enters piston
end of both crawler pin pusher cylinders, extending each
cylinder rod, rotating each assembly lever to secure crawler
frame to carbody.
Hydraulic fluid exhausting from rod end of both crawler pin
pusher cylinders returns to lower accessory valve and is
returned to tank.
Right Crawler Pin-Pusher Cylinders Disengage
Move right crawler pins lever (1) forward to disengage
position to retract crawler pin pusher cylinders (2) from
crawler track frame. This shifts selected carbody lower
accessory valve to block charge pressure to accessory
pressure switch (4).
The accessory pressure switch trips when the system
pressure drops to 120 psi (8,3 bar), sending an input signal
to the PC. The PC sends a negative output voltage to rear
drum pump EDC that tilts rear drum pump swashplate to
stroke pump (3) in the low-pressure side direction. Low-
pressure side hydraulic fluid flows through the high-pressure
carry-over of accessory system valve where the system
pressure is 3,000 psi (207 bar). Hydraulic fluid enters rod
end of both crawler pin cylinders, retracting each cylinder
rod, releasing crawler track frame from carbody.
Hydraulic fluid exhausting from piston end of both crawler pin
cylinders returns to lower accessory valve and is returned to
tank.

Manitowoc 999 Specifications

General

Brand	Manitowoc
Model	999
Category	Construction Equipment
Language	English