Great Plains NP30A 30-foot Operator Manual - Manual (Page 54)

50 NP30A or NP40A Table of Contents Index Great Plains Manufacturing, Inc.
407-502M Table of Contents Index 2014-05-20
Re-Phasing Pull-Type Lift System
In typical use during a single application operation, it is
normal for the lift cylinders to get out of phase, resulting
in uneven raising and lowering of the fertilizer applicator.
Every 8 to 10 passes, re-phase the cylinders with this
procedure:
1. Raise the applicator completely, and hold the
hydraulic lever or switch in Extend for several
seconds after the applicator reaches full elevation.
2. When all cylinders are fully extended, momentarily
reverse (Retract) the control to lower the
applicator
1 ⁄
2
inch (12 mm).
3. Set circuit to Neutral to hold for level check.
If re-phasing does not bring the applicator into level,
other possibilities include:
• tire pressures too high or too low (page 139),
• worn tires,
• pull-type tongue height incorrect (page 38),
• 2-point tractor hitch height and level incorrect,
• 2-point gauge wheel height incorrect (page 86),
• 2-point lift-assist height spacers incorrect or not
installed (page 38), and;
• gauge wheel / lift-assist eyebolts (page 124)
• significant amounts of air in the hydraulic system,
indicating a need to perform a hydraulic bleed.
Figure 34
Re-phasing Cylinder Orifice
31521