Great Plains 3N-4025P Operator Manual - Manual (Page 151)

Great Plains Manufacturing, Inc. Table of Contents Index Maintenance and Lubrication 147
2014-01-29 Table of Contents Index 196-538M
Marker Maintenance
Overhead Hazard:
You may be injured if hit by a folding or unfolding marker.
Markers may fall quickly and unexpectedly if the hydraulics
fail. Never allow anyone near the drill when folding or
unfolding the markers.
See also:
“Marker Setup (Option)” on page 21 and
“Marker Adjustments” on page 94.
If grease-seal cap for marker-disk-hub bearings is
damaged or missing, disassemble and clean hub.
Repack with grease and install a new seal or grease cap.
Bleeding Markers
Review hydraulic bleeding warnings and advisories on
page 145.
To fold properly, the marker hydraulics must be free of
air. If the markers fold in jerky, uneven motions, follow
these steps.
1. Check that tractor hydraulic reservoir is full.
2. With both markers lowered into field position, loosen
hydraulic-hose fittings at rod and base ends of
marker cylinders. If applicable, loosen fittings on
back side of sequence valve.
3. With tractor idling, activate tractor hydraulic valve
until oil seeps out around a loosened fitting. Tighten
that fitting.
4. Reactivate tractor hydraulic valve until oil seeps out
around another loosened fitting. Tighten that fitting.
Repeat process until all loosened fittings have been
bled and tightened.
Marker Speed
The procedure for adjusting marker speed is different for
single marker with needle valve and dual markers with
sequence valve.
Single Marker/Needle Valve Speed
Refer to Figure 201
A needle valve controls the folding speed. The needle
valve is near the rod end of the marker cylinder.
With tractor idling at a normal operating speed, adjust
marker folding to a safe speed. Turn adjustment knob
clockwise to reduce folding speed or counterclockwise to
increase folding speed. Excessive folding speed could
damage markers and void the warranty.
Figure 200
Marker
20306
Figure 201
Needle valve Adjustment
15625