Great Plains 3S-4000F Operator Manual - Manual (Page 32)

28 3S-4000 Table of Contents Index Great Plains Manufacturing, Inc.
195-394M Table of Contents Index 2014-06-10
Setting the Bypass Valve
Refer to Figure 20
A bypass valve is plumbed into the opener down
pressure 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 hydraulic system is on
your tractor, contact your tractor manufacturer.
Tractors with Open Center Hydraulics
Close bypass valve for no oil flow by turning knob on
valve clockwise completely. Always operate the drill with
the bypass valve closed.
Tractors with Pressure Compensating Closed Center
Hydraulics (PC Closed)
Close bypass valve for no oil flow by turning knob on
valve clockwise completely. Always operate the drill with
the bypass valve closed.
Tractors with Load Sensing Closed Center
Hydraulics (LS Closed) or Pressure Flow
Compensating (PFC) Systems
Equipment Damage Risk:
Failure to use the bypass valve on load-sensing tractors may
cause major tractor damage.
1. Close bypass valve for no oil flow by turning knob on
valve clockwise completely.
2. With tractor at half throttle, adjust flow-control valve
on tractor so openers raise and lower at a
reasonable speed. Keep tractor at one-half throttle
for remaining steps.
Note: The faster openers raise and lower, the greater
potential for oil heating, premature wear or tractor
damage.
3. Engage tractor hydraulics and lower openers. Lock
hydraulic lever on tractor for continuous operation.
Figure 20
Bypass Valve
19045
1