Great Plains YP925TD Operator Manual - Manual (Page 88)

84 YP625TD and YP925TD Table of Contents Index Great Plains Manufacturing, Inc.
401-755M Table of Contents Index 02/23/2011
Lift Cylinder Bleeding
If lift assist movement is jerky, there may be air in the
system.
Refer to Figure 88
1.
Consult lift circuit hydraulic diagram on page 108
(repeated at right in smaller scale)
2. Check that tractor hydraulic reservoir is full. Set
hydraulics for low flow rate.
3. If lock channel is installed on lift cylinder rod, raise
planter and remove lock (page 20).
4. Keep 3-point hitch raised, so that lift-assist cylinder
can completely retract.
5. Lower rear of planter.
6. Loosen the JIC fitting at the base end (top) of the
lift cylinder.
7. Extend the lift circuit (as if to raise) until fluid appears
at the loosened fitting or until the hose is free of air.
When fluid appears consistently, set control lever to
Neutral and secure the JIC fitting.
8. Full raise the planter. Install the lift cylinder lock. Set
the lift circuit to Neutral.
9. Loosen the JIC fitting at the rod (bottom) end of
the lift cylinder.
10. Retract the circuit (as if to lower) until fluid appears at
the loosened fitting or until the hose is free of air.
When fluid appears consistently, set control lever to
Neutral and secure the JIC fitting.
11. Raise the planter. Remove the lock channel.
12. Extend and retract the circuit several times.
Drive-Line Shear Pin
Refer to Figure 89
The spirol pin
that connects main transfer shaft
collar to the transmission shears if an excessive load
is put on the shaft.
Infrequent or improper lubrication causes binding of
moving parts within the planter. This binding can cause
the spirol pin to shear, preventing more serious damage
to other planter parts.
Machine Damage / Nuisance Shear Risks:
Do not use arbitrary spirol pins. Replace sheared pins with
cotter pins of the same size. Strong pins may fail to shear,
causing more serious damage elsewhere. Weaker pins are
prone to nuisance shears. Refer to current Parts Manual for
correct spirol pin replacement part number.
Figure 88
Bleeding Lift System
31881
2
1
1
2
Figure 89
Transmission Shear Pin
29884
2
1
1
2