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Maintenance and Lubrication
2019-01-23
3P806NT 313-520M
47
Bleeding Hydraulics
High Pressure Fluid Hazard:
Escaping fluid under pressure can have sufficient pressure 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 paper or cardboard, not body parts,
and wear heavy gloves to check for suspected leaks. If injured,
seek immediate medical attention from a physician familiar
with this type of injury.
Check that tractor hydraulic reservoir is full.
Bleed pressurized lines only at:
JIC (Joint Industry Conference, 37
flare) or
NPT (National Pipe Thread, tapered thread) fittings.
Avoid bleeding at:
ORB (O-Ring Boss)
Never bleed pressurized lines at:
QD (Quick Disconnect) fittings.
1. Check hydraulic fluid in tractor reservoir and fill
reservoir to proper level. Add fluid to system as
needed. A low reservoir level may introduce air into
the system, causing jerky or uneven cylinder
movements.
2. Hitch drill to tractor (page 14).
3. If lift-assist lock channel or stroke control spacers are
installed, raise drill and remove them.
4. Fully lower drill (page 19).
5. Set tractor lift circuit to Float and shut off tractor.
6. Crack (slightly loosen) JIC connection at elbow
fitting.
7. Start tractor. Slowly Extend lift-assist circuit until oil
seeps at cracked fitting.
8. Set circuit to Neutral and shut off tractor.
9. Tighten JIC fitting to 18-20 ft-lbs (24-27 N-m).
10. With cylinder bled and tightened, raise drill and
re-install removed lock channel or spacers.
Figure 38
Lift-Assist System Bleed
32056
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