Great Plains 3P4025AH Operator Manual - Manual (Page 54)

50 3P4025AH Table of Contents Index Great Plains Manufacturing, Inc.
411-099M Table of Contents Index 2014-07-29
Hydraulic Down-Float Adjustments
(Option)
For the hydraulic down-pressure option, see “Hydraulic
Down Pressure (Option)” on page 46. The wing
flex-lock option has no adjustments.
This option allows the wings to float up and down by 7.5
°
in gently rolling fields. The cylinders hold the wings at or
slightly above level during field lift.
Refer to Figure 38
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 long clevis slots.
If the planter does not have lift-assist
a
, there are no
adjustments for this system.
Down-Float Lift-Assist Sequencing
The lift-assist needle valve assures that the down-float
system raises before the Lift-Assist raises. This prevents
lateral dragging of openers in field lift. Sequencing during
lower is controlled by the PO check valve
and has no
adjustment.
The needle valve requires an initial setup, possible
re-adjustment for different field conditions, and a
seasonal check.
Setup/adjustment requires moving the planter to field
conditions, hitched to a tractor. Empty seed hoppers are
preferred for this adjustment, but not essential.
Initial Needle Valve Setup
Perform step 2 only on first use of the planter, or if the
needle valve itself required maintenance.
You will need a hex key/wrench for the set screw. Hex
key size may vary with valve brand. If the valve has two
set screws, loosen the one closer to the valve body.
1. At the needle valve , loosen the set screw .
2. Turn the valve knob fully clockwise, then
counter-clockwise one turn.
3. Unfold the planter. Install the Wing Lock pins
(page 22). With the 2-point hitch raised, retract the
down-pressure/lift-assist circuit to lower.
4. Carefully extend the circuit for lift-assist, observing
whether wing lift to level occurs prior to lift, and that
lift occurs at a reasonable rate.
If lift occurs before wings-level, turn the needle valve
knob
1 ⁄
4
turn clockwise to reduce lift flow to the
lift-assist cylinders.
If lift is too slow, turn the needle valve knob
1 ⁄
4
turn
counter-clockwise to increase lift flow to the lift-assist
cylinders. Do not add so much flow that lift occurs
before wings-level.
5. When satisfied with lift sequence and rate, secure
the needle valve set screw.
Further Needle Valve Adjustment
6.
Verify field lift sequence and rate with full hoppers
when afield. Conversely, if the adjustment was
initially made with full hoppers, verify sequence and
rate as they empty.
a. A planter with the hydraulic down-pressure has this valve installed even if lift-assist is not present.
If lift-assist is not present, the line is plugged at the valve and no adjustment is necessary.
Figure 38
Down Float Hydraulics
36148
1
2
3
4
1
2
3
2 4