Hydraulic down pressure calibration, Pc closed down pressure – Great Plains 3PYP Operator Manual User Manual
Page 159
Great Plains Manufacturing, Inc.
Appendix C: Initial Setup
155
2014-09-09
401-312M
Hydraulic Down Pressure Calibration
Refer to Figure 148
If your planter is equipped with the optional hydraulic
down pressure system, it needs an initial/seasonal setup.
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.
Note: The hydraulic down pressure kit is integrated with
the lift assist system. When the down pressure
system cycles, the planter raises and lowers.
There are two adjustable valves in the system:
Bypass valve
located near parallel arms
Adjustment valve
located near hitch
PC Closed Down Pressure
Tractors with Pressure Compensating Closed Center
Hydraulics (PC Closed)
Refer to Figure 148
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 148: s/n A1025S+
Hydraulic Down Pressure Valves
29803
2
3
4
1
1
2
3
1
4
3