Great Plains 3N-4025P Operator Manual - Manual (Page 19)

4/23/2010 196-286M
17 Preparation and Setup
Bleeding Hydraulics
Escaping fluid under pressure can have sufficient pres-
sure to penetrate the skin. Check all hydraulic lines
and fittings before applying pressure. Fluid escaping
from a very small hole can be almost invisible. Use pa-
per or cardboard, not body parts, and wear heavy
gloves to check for suspected leaks. If injured, seek
medical assistance from a doctor that is familiar with
this type of injury. Foreign fluids in the tissue must be
surgically removed within a few hours or gangrene
will result.
Bleeding Lift Hydraulics
The lift system is equipped with rephasing hy-
draulic cylinders that require a special procedure
for bleeding air from the system. Read and follow
the procedure carefully.
1. Check hydraulic fluid level in tractor reservoir
and fill to proper level. Add fluid to system as
needed while cycling new cylinders.
2. Lower drill to ground.
3. Unpin rod ends of wheel cylinders. Pivot cyl-
inders up and wire or otherwise safely sup-
port rod ends higher than base ends. You may
need to remove the gauge-wheel cylinders
from the rockshaft so you can orient them with
rod ends higher than base ends.
4. With the tractor engine at idle speed, energize
the lift hydraulics. When the cylinders have
extended completely, hold the remote lever
on for one minute. Check all hydraulic hoses,
cylinders and fittings for leaks.
5. Retract the cylinder rods. Extend the rods
again and hold the remote lever on for one
more minute. Repeat this step two more
times.
6. Again, check all hydraulic hoses, cylinders
and fittings for leaks. Recheck the tractor hy-
draulic reservoir. Fill to the proper level.
7. Repin all cylinders.
Bleeding Fold and Lock Cylinder Hydraulics
The fold system is equipped with rephasing hy-
draulic cylinders that require a special procedure
for bleeding air from the system. Read and follow
the procedure carefully.
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:
1. Unpin the small lock cylinders, pivot cylinders
so the rod end is free to move.
2. Crack fittings at base end of cylinders. Extend
cylinders to purge air from system.
3. Crack fittings at rod end of cylinders. Retract
cylinders to purge remaining air from system.
4. Repeat steps one and two.
5. Repin small lock cylinders.
Fold cylinders:
Note: Unfolding drill retracts fold cylinders.
6. Unpin rod ends of wheel cylinders. Pivot cylin-
ders up and wire or otherwise safely support
rod ends higher than base ends. You may
need to remove the gauge-wheel cylinders
from the rockshaft so you can orient them with
rod ends higher than base ends.
7. With the tractor engine at idle speed, energize
the lift hydraulics. When the cylinders have ex-
tended completely, hold the remote lever on
for one minute. Check all hydraulic hoses, cyl-
inders 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 fittings for leaks. Recheck the tractor hy-
draulic reservoir. Fill to the proper level.
10. Repin all cylinders.
Never bleed an O-ring fitting. Instead, bleed a nearby
pipe or JIC fitting.
JIC fittings do not require high torque. JIC and O-ring
fittings do not require sealant. Always use liquid pipe
sealant when adding or replacing pipe-thread fittings.
To avoid cracking hydraulic fittings from over tighten-
ing, do not use plastic sealant tape.