Great Plains 2SF30 Operator Manual - Manual (Page 22)

18 2SF24/30 Table of Contents Index Great Plains Manufacturing, Inc.
155-015M-A Table of Contents Index 2014-01-09
Bleeding The Hydraulic Systems
Equipment Damage Risk:
The SAE O-RING and JIC 37˚ FLARE type hose connections
DO NOT require sealant for reconnecting. They DO NOT
require high torque for a good seal.
When using sealant on pipe threads the friction between the
threads is reduced; therefore, be certain not to over tighten,
causing damage to a valve, cylinder port or fitting.
Elevating Mass Hazard:
This drill has a Negative Tongue Weight when unfolded and
raised. Be certain that the drill is hitched securely to your
tractor draw bar and be certain the hitch safety chain is
securely attached to the drill hitch and tractor before raising
or unfolding the drill!
Bleeding the Lifting Hydraulic System
This 2SF24/30 is equipped with rephasing type hydraulic
lift cylinders that require a special procedure for bleeding
air from the hydraulic system. If your dealer has not
already prepared the cylinders for transport use, read the
following information carefully. The rephasing cylinders
will not function properly if this bleeding procedure is not
followed.
Note: DO NOT crack hose fittings in order to bleed air
from this system.
Equipment Damage Risk:
Check the hydraulic fluid level in the tractor reservoir and fill
to the proper level before starting this procedure. If the
bleeding is performed with a low reservoir supply, there is a
chance of drawing air into the system. System capacity is
approximately 3.3 gallons and requires one pair of remote
outlets.
1. If required, raise your drill 1 inch in order to extend
your lift cylinders a little. Loosen the jam nuts on top
of the transport vertical tubes and screw the
adjustment screw in until it bottoms. Lower the drill
until the cylinders become loose.
2. Unpin the cylinders from the mainframe and turn the
cylinders upside down to a position where the rod
end is higher than the base end. Support the
cylinders in a safe location. One transport tire may
have to be removed in order to unpin the master
cylinder.
3. Start the tractor and run the engine at idle. With the
rod end of the cylinders higher than the base end,
hydraulically extend the cylinders and hold the
tractor control lever in position for sixty seconds after
the cylinders have extended to their maximum
stroke.
4. Hydraulically retract the cylinders, then repeat the
extending procedure several more times until both
cylinders are free of air and operate together.
5. Repin the cylinders to the main frame and axle with
the rod end down. If air is tapped in either cylinder,
the affected cylinder will have a spongy, erratic
movement and the machine will not raise evenly.
Refill the tractor hydraulic fluid reservoir to its proper
level.
Note: After drill is raised, a slight settling will occur due
to the action of the rephasing cylinder.
Note: In order to prevent trapped air pockets, the port on
the rod end must be higher than any other port of
the cylinder during the bleeding operation.
Note: The folding and transport/wing lift cylinders are not
rephasing type cylinders and do not require this
bleeding procedure.