Great Plains NTA2007 Operator Manual - Manual (Page 138)

134 NTA607 or NTA2007 Table of Contents Index Great Plains Manufacturing, Inc.
166-372M Table of Contents Index 2012-01-05
Marker Maintenance (Option)
Review “Marker Safety Information” on page 62 before
performing maintenance on markers.
See also:
“Marker Operation (Option)” on page 62 and
“Marker Adjustments” on page 99.
Marker Shear Bolt
Refer to Figure 125
The marker arm is attached to the pivot sleeve with a
shear bolt
, which is intended to fail if the marker
strikes an obstruction, allowing the marker to swing back
around a normally stationary pivot
.
If the shear bolt breaks, replace it with an equivalent:
5 ⁄
16
-16x4in Grade 5 bolt (Great Plains part 802-223C).
If that size is not immediately available in your area,
temporarily substitute an M10x10.0 Class 8.8 metric bolt.
Use two nuts
on the shear bolt.
Note: Replacing the bolt with a lower grade, or smaller
size, or using a single nut, can result in nuisance
shears.
Machine Damage Risk:
Replacing the bolt with a higher grade can result in marker
damage.
Marker Hydraulic Bleeding
1. Review warnings, bleeding notes and system
information on page 119.
Refer to Figure 126
2.
With markers unfolded in field position, crack
hydraulic-hose JIC fittings at base
and rod
ends of each marker cylinder.
3. With tractor at idle speed, activate tractor hydraulic
valve forward until oil appears at a fitting. When oil
begins to seep out around a fitting, tighten that
fitting. Reverse the tractor hydraulic valve until oil
appears at opposite hose fitting. Tighten that fitting.
4. Activate tractor hydraulic valve forward again until oil
seeps out around a fitting on the other marker
cylinder. Tighten that fitting. Reverse tractor
hydraulic valve until oil seeps out around remaining
hose fitting and tighten it.
5. Fold and unfold markers slowly to work out all air.
Note: Use caution when folding and unfolding markers for
the first time, checking for pinching and kinking of
hoses.
Figure 125
Marker Shear Bolt
31316
Crush / Pinch / Knock-Down Hazards:
You may be injured if trapped or hit by a folding or unfolding
marker. Never allow anyone near the drill when folding or
unfolding markers.
2
1
3
3
1
2
3
Figure 126
Marker Bleed Points
31344
4
5
4
5