GREAT PLAINS Yield-Pro Air-Pro YP2425A, Operator'S Manual

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YP2425A Table of Contents Index Maintenance and Lubrication
Great Plains | 401-626M | 2019-06-11 Table of Contents Index 107
Bleeding Hydraulics
High Pressure Fluid Hazard:
Relieve pressure before disconnecting hydraulic lines. Wear
protective gloves and safety glasses or goggles when working
with hydraulic systems. Escaping fluid under pressure can
have sufficient pressure to penetrate the skin causing serious
injury. Use a piece of paper or cardboard, NOT BODY PARTS,
to check for leaks. If an accident occurs, seek immediate
medical attention from a physician familiar with this type of
injury.
Only trained personnel should work on system hydraulics!
System Contamination Risk:
Always use liquid pipe sealant when adding or replacing NPT
(National Pipe Thread, tapered thread) pipe-thread fittings. To
avoid cracking hydraulic fittings from over tightening, and to
keep tape fragments from clogging filters, do not use plastic
sealant tape.
Fold System Bleeding
Machine Damage Risk:
Raise planter completely before folding or unfolding.
Normally the fold hydraulics are bled at the factory
before shipping, and bleeding should not be required
other than to fold fully and hold lever on for one minute or
until all cylinders reach the end of their stroke.
Erratic gage wheel behavior, such as wandering back
and forth in the field, or failing to rotate fully into place
while folding, are signs that the fold cylinders need to be
bled.
Fold Cylinder Bleeding
Refer to Figure 142
1. Begin with planter raised and lift cylinder locks
installed.
2. Unpin cylinder rod ends. Orient cylinders so that rod
ends may extend without striking planter parts.
3. Loosen the JIC fittings , at the base end of all
cylinders.
4. Extend the circuit until liquid (non-foamy) appears at
the loosened fittings and cylinders are fully
extended. Set circuit to Neutral and secure fittings.
5. Loosen the JIC fittings , at the rod end of all fold
cylinders.
6. Retract the circuit until fluid appears at all fittings. Set
circuit to neutral and secure fittings.
7. Extend cylinders and re-pin cylinder rod ends.
JIC Torque Chart
Over-Torque Leak Risk:
JIC (Joint Industry Conference 37° Flare) fittings do not
require high torque. Excess torque causes leaks. JIC and
ORB (O-Ring Boss) fittings do not require sealant.
 Bleed only at JIC and NPT fittings.
Never try to bleed a QD (Quick Disconnect) fitting.
Avoid bleeding at ORB fittings, as the O-ring is likely
to be torn if any pressure remains in the circuit.
Size Foot-Pounds N-m
7
/
16
-20
11-12 15-16
3
/
8
-20 15-16 20-22
9
/
16
-18
18-20 24-28
3
/
4
-16 38-42 52-58
7
/
8
-14
57-62 77-85
11
/
16
-12
79-87 108-119
Figure 141
Lift Bleed
25227
1
2
1
2
1 2
3 4