Great Plains 2551SC Operator Manual - Manual (Page 21)

Great Plains Manufacturing, Inc. Operating Instructions 17
10/09/2013 540-179M
Hydraulic Down Pressure
Refer to Figure 8
Note: This setup procedure is for tractors with closed-
center or pressure compensated flow hydraulic
systems. Do Not Use with open-center hydraulics.
Use optional wing weights.
5. Adjust the bypass/pressure reducing valve by turning
knob
, clockwise all the way in and then backing
out 1 full turn.
6. On tractor, adjust flow-control valve to low side of
flow rate.
Note: The faster the flow of oil through the system the
greater potential for oil heating, premature wear or
tractor damage.
7. Lock the fold hydraulic lever for continuous down-
ward oil flow.
8. Adjust bypass/pressure reducing valve knob on
implement so the pressure gauge reads 1400 psi.
Never exceed 1600 psi.
9. While watching pressure gauge, slowly open valve
knob
until gauge reads 1300 psi. Pressure might
rise and then fall off as knob is opened. If pressure
exceeds 1600 psi during this step, the tractor flow is
too high, reduce tractor flow. Lock valve knob
at
1300 psi.
10. Finally adjust valve to the desired wing down pres-
sure setting of 800 to 1000 psi. Never exceed 1200
psi.
11. In field operation, Lock the fold hydraulic lever for
continuous downward oil flow. If wings are running
too high, increase pressure setting, knob
, to level
machine. If center is too high, decrease pressure
setting with knob
on valve.
Never leave hydraulic lever centered while in field mode.
Machine damage may occur when wings flex. Use continuous
down or float.
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Figure 8
Hydraulic Down Pressure 42294
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