Priority flow hydraulic systems, Non-active hydraulic systems – Great Plains 3S-4000HDF Operator Manual User Manual
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3S-4000HD/HDF
Great Plains Manufacturing, Inc.
195-067M
2013-06-13
Priority Flow Hydraulic Systems
On some tractors with load-sensing hydraulics, the
circuit #1 is capable of taking nearly 100 percent of
available hydraulic flow. Operating the openers or
markers on circuit #1 will starve the other circuit, making
one function inoperable.
To operate markers and constant opener down pressure
at the same time, connect the openers to circuit #2 and
the markers to circuit #3.
Non-Active Hydraulic Systems
To run drill with open-center hydraulics or
fixed-displacement hydraulic pumps requires a Great
Plains kit, part number 194-143A. After installing the kit,
refer to the following instructions for opener operation.
1.
Lower opener frames by pushing forward on tractor
hydraulic lever. Lock lever temporarily in this position
while adjusting opener down pressure.
Refer to Figure 29
2.
With tractor hydraulic lever locked forward, release
lock disk
and set down pressure with adjustment
knob
. Watch pressure gauge and dial in desired
pressure on openers. There is one pressure-control
valve for openers on center section and one for
openers on wing sections of drill.
Note: Rotate knob clockwise to increase pressure and
counterclockwise to decrease pressure.
3.
Once pressure is set, set knobs with lock disks
.
4.
After opener down pressure is set, return tractor
hydraulic lever to neutral. This locks-in the selected
pressure, and opener frames remain fixed in this
position.
Equipment Damage Risk:
Open-center tractors and tractors with fixed-displacement
pumps are not designed to provide a continuous supply of
pressurized oil to remote valves. Locking hydraulic lever
forward on these tractors can cause overheating of hydraulic
oil and tractor damage. After setting opener down pressure,
always return hydraulic lever to neutral.
Note: On some tractors with very positive remote
hydraulic checks, a slight increase in the reading on
the pressure gauges may occur after tractor remote
lever is returned to neutral. This is caused by back
pressure on opener cylinders and should be
ignored. The net operating pressure on opener
cylinders is maintained at the pressure you
selected while tractor remote lever was held
forward-not at the apparently increased pressure.
Reactivating tractor lever forward will confirm this.
Figure 29 - Non-Active
Pressure Control Valves
26477
1
2
1
2
1