Great Plains 3PYP Operator Manual - Manual (Page 163)

Great Plains Manufacturing, Inc. Table of Contents Index Appendix D: Older Equipment 159
2014-09-09 Table of Contents Index 401-312M
Hydraulic Down Pressure Calibration
Refer to Figure 154, Figure 155 or Figure 156
If your planter is equipped with the optional hydraulic
down pressure system, it needs an initial/seasonal setup.
Depending on the serial number of your planter the
hydraulic down pressure system will look like one of
three illustrations here.
There are two adjustable valves in these systems:
Bypass valve
located near parallel arms
Adjustment valve
located near hitch
Note: The hydraulic down pressure kit is integrated with
the lift assist system. When the down pressure
system cycles, the planter raises and lowers.
PC Closed Down Pressure
(S/N A1007S to A1024S)
Tractors with Pressure Compensating Closed Center
Hydraulics (PC Closed)
Refer to Figure 154
1. Release locking disk .
2. Close bypass valve for no oil flow by turning
knob on valve clockwise completely.
3. Tighten locking disk . Always operate the planter
with the bypass valve closed.
No further adjustments are made at this time. See
“Hydraulic Down Pressure” on page 52 for field
operations.
Figure 154: s/n A1007S to A1024S
Hydraulic Down Pressure Valves
27371
1
2
3
4
Equipment Damage Risk:
If your tractor has Open Center hydraulics, do not engage the
down pressure hydraulics. The current hydraulic down
pressure option is compatible only with tractors having Closed
Center systems.
1
2
3
1
4
3