Great Plains 3PYP Operator Manual - Manual (Page 56)

52 3PYP Table of Contents Index Great Plains Manufacturing, Inc.
401-312M Table of Contents Index 2014-09-09
Hydraulic Down Pressure
Refer to Figure 53
If the desired opener depth cannot be consistently
achieved using spring adjustment (page 62), or the
gauge wheel is slipping at the force required, the optional
hydraulic down pressure may remedy the problem. It
uses two cylinders to transfer more weight to the wings.
Equipment Damage Risk:
The current hydraulic down pressure option is compatible only
with “closed center” tractor hydraulics.
Before making depth adjustments with valve , make
sure the system (valve ) has been calibrated. See
“Hydraulic Down Pressure Calibration” on page 159.
To adjust hydraulic down pressure:
1. Set the mechanical (cam spring) down pressure to
notch 3. See “Row Unit Down Pressure” on
page 61.
2. The remote lever must be LOCKED OPEN in this
position to provide constant pressure/flow to the
openers.
3. With the tractor hydraulic lever locked forward,
release the lock disk
, turn the knob on the
pressure control valve .
4. Watch the pressure gauge and 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
.
Note: Refer to “Hydraulic Down Pressure Calibration”
on page 159 to know what to expect the planter to
do as hydraulics are cycled.
The recommended pressure range for planting is
between 400 psi and 600 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.
John Deere 8000 Series tractors:
Set timer to continuous. Push lever forward until detent
clicks.
Case IH
®
Magnum™ tractors:
Lock lever forward in detent position. You may need to
turn up detent pressure to its maximum setting. Do not
tie hydraulic lever past detent position with a strap. See
your tractor dealer for hydraulic-system details.
Other tractors:
Lock lever forward in detent position. You may need to
turn up detent pressure to maximum or use a mechanical
detent holder to hold lever forward. See your tractor
dealer for providing constant flow to openers.
Figure 53: s/n A1025S+
Hydraulic Down Pressure Valves
29194
1
1
c
4
2
3 1
c
2 3
1
4
2