Great Plains 3P4025AH Operator Manual - Manual (Page 53)

Great Plains Manufacturing, Inc. Table of Contents Index Adjustments 49
2014-07-29 Table of Contents Index 411-099M
Down-Pressure Adjustment
Refer to Figure 37
Before optimizing the down-pressure (pressure reducing)
valve setting
, make sure the lift-assist needle valve
(if lift-assist is installed) and the bypass valve have
been set up. See previous pages.
To adjust hydraulic down pressure:
1. If not already done, unfold and lower the planter in
field conditions. Install the Wing Lock pins (page 22).
2. Set the row unit mechanical (spring) down pressures
per conditions (see page 52). This may be easier
with the planter raised.
Note: For the next step, the remote lever must be
LOCKED OPEN in this position to provide constant
pressure/flow to the down pressure system.
3. With the tractor hydraulic lever locked forward,
release the lock disk
, turn the knob
counter-clockwise on the pressure reducing valve .
4. Watch the pressure gauge. Set the desired pressure.
Clockwise increases the pressure and
counterclockwise decreases pressure.
5. Once the pressure is set, lock the knob with the lock
disk
.
The suggested initial pressure range for planting is
between 200 psi and 400 psi.
The opener pressure setting controls the soil firming
pressure on the press wheel as well as the disk
penetrating force. DO NOT use more opener down
pressure than necessary to obtain the desired opener
penetration and to maintain the proper firming action
over the seed. Excessive opener force will lead to
excessive wear and damage of the opener components.
Figure 37
Down Pressure Field Adjust
36147
2
3
1
7
8
3 1
2
7 8
3
7