Great Plains V-300F Operator Manual - Manual (Page 103)

Great Plains Manufacturing, Inc. Maintenance and Lubrication 99
11/15/2007 148-057M-A
Bleeding Transport Lift Cylinders
The transport-lift cylinders are rephasing cylinders and
require a special procedure for bleeding air from the cir-
cuit. Read and follow procedure carefully. Cylinders do
not function properly with air in the hydraulic circuit.
1. Check hydraulic fluid in tractor reservoir and fill to
proper level. Add fluid to system as needed. Trans-
port-lift-cylinder capacity is about 7.57 liters (2 gal-
lons).
2. Jack up and support hitch frame.
3. Set hydraulic circuit for lift and down-pressure to
Float.
Refer to Figure 109
4.
Disable the down-pressure cylinder:
Release lock disk and set down-pressure valve to
zero (turn knob fully counter-clockwise).
Release lock disk and close bypass valve (turn
knob fully clockwise).
Refer to Figure 110
5.
Remove the retaining clips from the pins at both
ends of the cylinders for both transport lifts.
6. Turn cylinders to a position where rod ends are
higher than base ends. Support cylinders in a safe
location.
7. Start tractor and run engine at idle speed. With rod
ends higher than base ends, hydraulically extend cyl-
inders. After cylinder rods are fully extended, con-
tinue to hold control lever for one minute before
hydraulically retracting cylinders.
8. Repeat step 7 three times to completely bleed sys-
tem. If air is still trapped in either cylinder, it will oper-
ate in jerky, erratic motions. Repeat steps until
cylinder movement is smooth and even.
9. Re-pin cylinders to the transport lift.
10. Refill tractor hydraulic-fluid reservoir to proper level.
11. If the down-pressure cylinder is to be bled next, skip
to step 12.
If down-pressure cylinder will not be bled at this time,
re-calibrate the down pressure (page 22), then
restore your preferred pressure setting (page 36).
Figure 109
Down-Pressure Valves
27267
1
3
4
2 1
2
3
4
Figure 110
Lift Cylinder Un-Pin & Rotate
27177