Great Plains NTA2007HD Operator Manual - Manual (Page 134)

130 Great Plains Manufacturing, Inc. Contents Index NTA607/2007HD
166-283M Contents Index 04/04/2011
Marker Maintenance (Option)
Review “Marker Safety Information” on page 59 before
performing maintenance on markers.
See also:
“Marker Operation (Option)” on page 58 and
“Marker Adjustments” on page 94.
Marker Shear Bolt
Refer to Figure 127
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, tem-
porarily 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 infor-
mation on page 114.
Refer to Figure 128
2.
With markers unfolded in field position, crack hydrau-
lic-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 fit-
ting. 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 cylin-
der. 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.
Null4:
Figure 127
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
Null4:
Figure 128
Marker Bleed Points
31344
4
5
4 5