Great Plains 2S-2600HDF Operator Manual v2 - Manual (Page 23)

Great Plains Manufacturing, Inc. Table of Contents Index Preparation and Setup 19
2014-02-03 Table of Contents Index 195-069M
Setting the Bypass Valve
Refer to Figure 12
A bypass valve
is plumbed into the opener down pres-
sure circuit. Tractors with load-sensing, closed-center
hydraulics require this bypass valve to protect the tractor
hydraulic system. If you are unsure what type of hydrau-
lic system is on your tractor, contact your tractor manu-
facturer.
“CENTER” are the two inside opener lift cylinders.
“WING” are the two outside opener lift cylinders.
If the Point Row option is installed, these controls are
re-plumbed as entire “LEFT” and “RIGHT” wings.
Turn the locking disc counter-clockwise to enable
adjustment. Turn the adjustment knob counter-clock-
wise to increase flow.
Turn the adjustment knob clockwise to decrease flow.
Turning it fully clockwise stops all bypass flow.
Tractors with Open Center Hydraulics
Release locking disc. Close bypass valve for no oil flow
by turning knob on valve clockwise completely. Tighten
locking disc. Always operate the drill with the bypass
valve locked closed.
Tractors with Pressure Compensating
Closed Center Hydraulics (PC Closed)
Release locking disc. Close bypass valve for no oil flow
by turning knob clockwise completely. Tighten locking
disc. Always operate the drill with the bypass valve
locked closed.
Tractors with Load Sensing Closed Center
Hydraulics (LS Closed) or Pressure Flow
Compensating (PFC) Systems
1. Release locking disc. Initially close bypass valve for
no oil flow by turning knob on valve clockwise com-
pletely.
2. With tractor at half throttle, adjust flow-control valve
on tractor so openers raise and lower at a reason-
able speed. Keep tractor at one-half throttle for
remaining steps.
Note: The faster openers raise and lower, the greater po-
tential for oil heating, premature wear or tractor
damage.
3. Engage tractor hydraulics and lower openers. Lock
hydraulic lever on tractor for continuous operation.
See “Raising and Lowering Openers” on page 24.
Equipment Damage Risk:
Failure to use the bypass valve on load-sensing tractors may
cause major tractor damage.
Figure 12
Bypass Valve
19045
1
2
3
1
2
3
3