Lift cylinder lock-up, Re-phasing lift system, Local float on hydraulic tongue – Great Plains YP4425A Operator Manual User Manual
Page 31

Great Plains Manufacturing, Inc.
Operating Instructions
27
2012-02-23
401-805M
Lift Cylinder Lock-Up
When moving the raised planter more than a short
distance, or over any public road, or when performing
adjustments or maintenance, do not rely solely on the lift
cylinders to keep the mainframe raised.
Install transport locks.
If planter is folded, confirm hitch is in Float.
If planter is unfolded, hitch may be in any
configuration.
2.
Raise the planter mainframe. See “Raising/
Lowering Planter” on page 25.
3.
Remove the transport locks from their storage
positions
. Install the transport locks on the
cylinder rods
, securing them with the same pins
used for storage.
4.
Lower the lift cylinders onto the locks.
Re-Phasing Lift System
In typical use during a single planting operation, it is
normal for the lift cylinders to get slightly out of phase,
resulting in uneven raising and lowering of the YP4425A
Planter.
Every 8- to 10 passes, or if lifting is uneven, re-phase the
cylinders with this procedure:
1.
Raise the planter completely, and hold the hydraulic
lever or switch in Extend for several seconds after
the planter reaches full elevation, or until all cylinders
are fully extended.
2.
When all cylinders are fully extended, momentarily
reverse (Retract) the control to lower the planter
1
⁄
2
inch (13 mm).
Local Float on Hydraulic Tongue
A hydraulic hitch planter may be raised or lowered while
folded using the local float valve.
1.
Float hitch circuit before lowering while folded.
Float hitch circuit before rasing while folded.
2.
Set CFM Lift/Hitch switch to Lift for raising/lowering.
Close bypass valve
before switching to Hitch.
Hitch circuit operation has no effect with bypass
valve open.
Figure 25
Lift Cylinder Locks Installed
29283
1
2
Crushing Hazard:
Tongue or planter components may drop suddenly when circuit
is floated. Before raising or lowering, set CFM Lift/Hitch
switch to Hitch and set tractor circuit to Float. If tractor is not
available, use bypass valve on hitch.
Stand clear and open it slowly.
Figure 26
Local Float on Hydraulic Tongue
28477
3