Great Plains 3PYPA Operator Manual - Manual (Page 118)

114 3PYPA Table of Contents Index Great Plains Manufacturing, Inc.
401-647M Table of Contents Index 03/20/2012
Lift Cylinder Bleeding
Refer to Figure 135 and Figure 136.
Figure 135 depicts the parallel arms disconnected from
the seed support structure (on an earlier 3PYP model).
Disconnect only the cylinder rod end for bleeding.
Normally the lift hydraulics are bled at the factory before
shipping, and bleeding should not be required other than
to raise fully and hold lever on for one minute or until all
cylinders extend fully.
If the planter has wing flex cylinders or hydraulic down
pressure, bleed the small cylinders at the wing/center
coupling before bleeding the lift circuit. See “Wing Flex
Cylinder Bleeding” on page 115.
If necessary to further bleed system, follow these steps.
1. Consult the lift circuit hydraulic diagram for your
planter:
“Lift Hydraulics (Wing Lock)”, page 141,
“Lift Hydraulics (Wing Flex)”, page 142, or
“Lift Hydraulics (Weight Transfer)”, page 143.
(some partially repeated here for reference)
2. Check that tractor hydraulic reservoir is full. Set
hydraulics for low flow rate.
3. Lower planter.
4. Disconnect and lower rod ends of lift assist cylinders.
5. Extend the lift circuit until rods are fully extended. Set
circuit to Neutral.
6. Loosen the JIC fitting at the base end (top) of the
left lift cylinder.
7. Extend the lift circuit until fluid appears at the loos-
ened fitting. Set control lever to Neutral and secure
the fitting.
8. Loosen JIC fitting at base end of right lift cylinder.
9. Extend the lift circuit until fluid appears at the loos-
ened fitting. Set lever to neutral. Secure the fitting.
10. Retract the cylinders. Set circuit to Neutral. Elevate
both cylinders until the rod ends are higher than the
base ends.
11. Loosen JIC fitting at rod end of the left lift cylinder.
12. Retract the lift circuit until fluid appears at the loos-
ened fitting. Set control lever to neutral and secure
the fitting.
13. Loosen JIC fitting at rod end of right lift cylinder.
14. Retract the lift circuit again until fluid appears at the
loosened fitting. Set control lever to neutral and
secure the fitting.
15. Re-pin cylinders to seed cart lugs.
Null4:
Figure 135
Lift Assist Cylinders
29209
Null4:
Figure 136
Lift Cylinders
29112
1
2
3
4
L
R
1
2
3
4