Bleeding hydraulics – Great Plains 606NT Operator Manual User Manual
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3P605NT, 3P606NT, 605NT & 606NT
Great Plains Manufacturing, Inc.
151-061M
2014-02-10
Bleeding Hydraulics
Check that tractor hydraulic reservoir is full.
The drill lifting system is equipped with re-phasing type
hydraulic cylinders that require a special procedure for
bleeding air from the hydraulic circuits. Read and follow
this procedure carefully. Re-phasing type cylinders will
not function properly with air in hydraulic circuit.
1.
Check hydraulic fluid in tractor reservoir and fill
reservoir to proper level. Drill-system capacity is
about 1 gallon (4.5 liters). Add fluid to system as
needed. A low reservoir level may draw air back into
the system, causing jerky or uneven cylinder
movements.
2.
With drill attached to tractor, jack drill up and support
frame at ends near gauge wheels.
3.
With drill raised and supported, un-pin cylinders at
both gauge wheel arms and frame. Turn cylinders
rod end up. Wire or otherwise safely support rod
ends higher than base ends.
4.
With tractor engine idling, engage tractor hydraulics
to extend cylinder rods. When cylinder rods are
completely extended, hold remote lever on for one
minute.
5.
Retract cylinders. Extend cylinders again and hold
remote lever on for one more minute. Repeat this
step two more times to completely bleed system.
6.
Re-pin cylinders to drill frame and gauge wheel arm
with transport cylinder locks in place. If any air still is
trapped in either cylinder, the cylinder will have a
spongy, erratic movement and drill will not raise
evenly. If necessary, repeat bleeding process.
7.
Refill tractor hydraulic fluid reservoir to its proper
level.
High Pressure Fluid Hazard:
Escaping fluid under pressure can have sufficient pressure to
penetrate the skin. Check all hydraulic lines and fittings before
applying pressure. Fluid escaping from a very small hole can
be almost invisible. Use paper or cardboard, not body parts,
and wear heavy gloves to check for suspected leaks. If an
accident occurs, seek immediate medical assistance from a
physician familiar with this type of injury.
Note: In order to prevent trapped air pockets, rod end
must be higher than any other part of cylinder
during bleeding operation.
Note: After the drill is raised, a slight settling will occur
due to the action of the re-phasing cylinders.