Great Plains 3S-4000HDF Operator Manual - Manual (Page 63)

Great Plains Manufacturing, Inc. Table of Contents Index Adjustments 59
2013-06-13 Table of Contents Index 195-067M
Setting Hydraulic Down-Pressure
1. Lower openers to the ground. Lock hydraulic lever
forward for constant hydraulic flow.
You must lock hydraulic lever forward. See “Opener
Operation” on page 34.
Refer to Figure 62
2. Release lock disk . Turn knob on
pressure-control valve while watching pressure
gauge, turn knob until gauge shows desired
pressure. Turn clockwise to increase pressure. Turn
counterclockwise to decrease pressure.
There is one pressure-control valve for openers on
the center section and one for openers on the wing
sections of the drill.
Refer to the chart on page 58 for approximate force
at the openers for a given pressure setting. As a
general starting point, set hydraulic down pressure to
1600 psi. For most field conditions, adjust down
pressure between 1200 and 1800 psi.
Crop Population Risk:
Do not operate at pressures so high that the gauge wheels
loose traction, or are off the ground, resulting in skips and
poor seed metering.
3. Once pressure is set, lock knob with lock disk. If
using a non-active hydraulic system to run drill,
unlock the hydraulic remote lever and return it to
neutral.
Equipment Damage Risk:
On open-center tractors, after setting opener down pressure,
always return hydraulic lever to neutral. 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.
Figure 62
Down-Pressure Valves
26477
1
2
1 2