Great Plains 3N-4020 Operator Manual - Manual (Page 110)

106 3N-4010F/3N-4010HDF/3N-4020F Table of Contents Index Great Plains Manufacturing, Inc.
196-359M Table of Contents Index 2013-10-29
Bleeding Fold Hydraulics
Review hydraulic bleeding warnings and advisories on
page 105.
1. Check hydraulic fluid level in tractor reservoir and fill
to proper level. Add fluid to system as needed while
cycling new cylinders.
Lock Cylinders
Refer to Figure 147
2. The lock cylinders share a tractor remote circuit with
the Veris Drive system. To bleed the lock cylinders,
the selector valve handle must be rotated towards
the lock cylinder hoses to direct flow to that circuit.
3. Crack fittings at both the rod end and base end of the
small lock cylinders out on the LH wing and RH wing
wheel casters. See Hydraulic Diagram on page 130.
4. Activate the tractor lever for this circuit. When oil
appears at one fitting, stop and tighten that fitting.
Activate the same lever in the same direction until oil
appears on the other side of the drill. Tighten that fit-
ting.
5. Activate the tractor lever in the opposite direction
until oil appears at a fitting. Stop and tighten that fit-
ting. Activate the same lever in the same direction
until oil appears on the other side of the drill. Tighten
that fitting.
Fold Cylinders
Note: Unfolding drill retracts fold cylinders.
6. Unpin rod ends of wheel cylinders. Pivot cylinders up
and wire or otherwise safely support rod ends higher
than base ends. You may need to remove the fold
cylinders from the drill so you can orient them with
rod ends higher than base ends.
7. With the tractor engine at idle speed, energize the
fold hydraulics. When the cylinders have extended
completely, hold the remote lever on for one minute.
Check all hydraulic hoses, cylinders and fittings for
leaks.
8. Retract the cylinder rods. Extend the rods again and
hold the remote lever on for one more minute.
Repeat this step two more times.
9. Again, check all hydraulic hoses, cylinders and fit-
tings for leaks. Recheck the tractor hydraulic reser-
voir. Fill to the proper level.
10. Re-pin all cylinders.
Figure 147
Bleed: Drive/Lock Selector Valve
21844