Bleeding down-pressure hydraulics – Great Plains NTA3007 Operator Manual User Manual
Page 135

Great Plains Manufacturing, Inc.
Maintenance and Lubrication
131
2012-07-02
166-371M
Bleeding Down-Pressure Hydraulics
If the systems have sufficient fluid for safe operation,
prior to bleeding, perform unfold (page 34), tilt down
(page 39) and lower (page 42) operations. Set circuit to
Float.
1.
Review safety advisories and operational advice on
page 128, and on this page, before performing
bleed.
Fully close bypass valve
and Transfer valve
.
Fully open Wing
and Centre
transfer valves.
Un-pin six cylinder rod ends. Orient cylinders so that
rod ends may extend without striking drill parts.
4.
Fully retract cylinders. Set circuit to Neutral.
5.
Loosen the JIC fittings
at the base end of all
down-pressure cylinders.
6.
Slowly extend the circuit until fluid appears at a
loosened fittings. Set circuit to Neutral and secure
fittings. Repeat until all six fittings are secured.
7.
Fully extend cylinders. Set circuit to Neutral.
8.
Loosen the JIC fittings
at the rod end of all
down-pressure cylinders.
9.
Slowly retract the circuit until fluid appears at a
fitting. Set circuit to Neutral and secure fitting.
Repeat until all six fittings are secured.
10. Use tractor circuit to re-position rod ends and re-pin.
11. If bleeding is complete, restore bypass,
down-pressure and weight transfer valve settings
per:
See “Opener Down-Force (Hydraulic)” on
page 101.
Figure 128
Bleed: Down-Pressure Valves
29422
1
2
w
c
t
T
C
W
B
B
T
W
C
1
Figure 129
Fold Bleed Points
29484
2
2
1
2
1
2
2
2
1
1
1
2
2