Great Plains 3P4025AH Operator Manual - Manual (Page 50)

46 3P4025AH Table of Contents Index Great Plains Manufacturing, Inc.
411-099M Table of Contents Index 2014-07-29
Hydraulic Down Pressure (Option)
For hydraulic down-float, see “Hydraulic Down-Float
Adjustments (Option)” on page 50. The wing flex-lock
option has no adjustments.
If the desired opener depth cannot be consistently
achieved using spring adjustment (page 52), 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.
The system has four valves:
Refer to Figure 34
1.
Lift-Assist Needle Valve
a
(page 47)
This valve assures that the down-pressure system
brings the wings to level before the optional
Lift-Assist raises. It requires an initial setup and
seasonal check.
2. Bypass Valve (page 48)
This valve protects the system from over-pressure
on LS and PFC Closed systems. It requires a
one-time setup on PC Closed systems, and a
seasonal setup on LS and PFC Closed systems.
3. Pressure Reducing Valve (page 49)
This valve is used for routine field adjustment of
down-pressure.
4. Pilot-Operated Check Valve
a
This valve assures that wings lower after the optional
Lift-Assist lowers. It has no adjustments.
Equipment Damage Risks:
The current hydraulic down pressure option is compatible only
with “closed center” tractor hydraulics.
Before using the system for the first time, particularly if the
down-pressure feature was installed after delivery, verify that
the cylinder clevises
are connected to the wing pins using
the short clevis slots.
Note: The hydraulic down pressure kit is integrated with
the optional lift assist system. When the down
pressure system cycles, the planter raises and
lowers as the wings partially fold and unfold.
The down-pressure system requires a remote circuit
capable of continuous flow. Some tractors require
specific actions or lever accessories to accomplish this.
See side bar at right for details on selected models.
a. The PO Check valve, Needle valve, and associated mainframe hoses are present, with lines plugs, on planters without Lift-Assist.
They require no attention if Lift-Assist is not present. They are provided to support later installation of Lift-Assist.
Figure 34
Hydraulic Down Pressure Valves
36147
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.
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