Great Plains FH6800HD Operator Manual - Manual (Page 32)

28 FH6000HD Great Plains Manufacturing, Inc.
564-070M 04/28/2014
Bleeding Hydraulics
Normally the hydraulics are bled during final pre-delivery,
and bleeding should not be required prior to first use.
Bleeding may be required after hydraulic maintenance,
or if the hydraulic system is in an uncertain state.
1. Hitch the harrow to a tractor.
2. If the harrow is folded, verify that the wing lock
chains are engaged (page 16).
3. Connect the hydraulics to a hydraulic source, such
as a tractor remote.
4. Set the source circuit to Float to relieve any pressure
in the lines.
5. Disconnect both base and rod ends of all fold cylin-
ders.
6. Support the cylinders with ports facing up, and with
cylinders oriented so that rods cannot strike imple-
ment parts when at full extension.
7. Orient cylinders with base ends higher than rod
ends. Set circuit to Neutral.
One cylinder at a time:
8. Crack (slightly loosen) a JIC connection at a cylinder
base end.
9. Extend the circuit slowly until fluid appears at the fit-
ting.
10. Set the circuit to Neutral. Tighten the fitting.
11. Repeat step 8 through step 10 for the remaining cyl-
inders.
12. Retract the cylinders. Set circuit to Neutral.
13. Orient cylinders with rod ends higher than base
ends.
One cylinder at a time:
14. Crack (slightly loosen) a JIC connection at a cylinder
rod end.
15. Extend the circuit slowly until fluid appears at the fit-
ting.
16. Set the circuit to Neutral. Tighten the fitting.
17. Repeat step 14 through step 16 for the remaining
cylinders.
18. Set circuit to Float.
19. Re-pin base and rod ends of cylinders to center sec-
tion and wing lugs.
20. Test fold function carefully (page 16).
Crushing and Equipment Damage Hazards:
Bleed after servicing cylinders or their hoses. Air in the system
makes it hazardous to fold the implement. If it is necessary to
service hydraulics while folded, the first unfold is especially
dangerous. Wing motion can be uneven or jerky in fold.
Unfolding wings could fall suddenly. Anyone nearby could be
seriously injured or killed. Equipment damage is likely.
Negative Tongue Weight Hazard:
Make certain that harrow is securely hitched to a tractor
before unfolding. An unhitched harrow can tip over backwards
during folding and unfolding if the tongue is not secured.
High Pressure Fluid Hazard:
Wear safety goggles and gloves. The bleed procedure requires
partially opening pressurized hydraulic lines. Escaping fluid
under pressure can penetrate the skin, causing serious injury.
If an accident occurs, seek immediate medical assistance from
a physician familiar with this type of injury.