132
Great Plains Manufacturing, Inc.
NTA607/2007HD
166-283M
04/09/2019
Marker Maintenance (Option)
” on page 59 before
performing maintenance on markers.
See also:
Marker Shear Bolt
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
-16x4-in. 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 116.
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 cylin-
der. Tighten that fitting. Reverse tractor hydraulic
valve until oil seeps out around remaining hose fit-
ting 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 130
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
Null4:
Figure 131
Marker Bleed Points
31344
4
5
