Great Plains 2525A Operator Manual - Manual (Page 80)

76 2025A/2525A Table of Contents Index Great Plains Manufacturing, Inc.
118-999M Table of Contents Index 2013-06-04
Bleeding Marker Hydraulics
To function properly, the marker hydraulics must be free
of air. If hydraulics have not been bled, they will operate
with jerky, uneven motions and could cause markers to
drop rapidly during folding or unfolding. If hydraulics were
not bled during initial implement setup or if you replace a
part in hydraulic system during the life of the drill, com-
plete the following procedures.
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 medi-
cal 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.
Refer to Figure 82 (which depicts the left side of a dual marker
and sequence valve - the procedure is the same for single
markers and dual-singles)
1. Extend a marker on one side.
2. Disconnect the rod end at the marker arm.
3. Support the cylinder so that the rod cannot strike
anything over its full range of travel.
4. Supply oil until the rod is fully retracted.
5. Set circuit to neutral.
6. Carefully crack the JIC fitting at the base end.
7. Supply oil to Extend until the fitting seeps. Set circuit
to neutral and tighten fitting.
8. Supply oil until the rod is fully extended. Set circuit to
neutral.
9. Carefully crack JIC fitting at rod end of cylinder.
10. Supply oil to Retract until fitting seeps. Set circuit to
neutral and tighten fitting.
11. Adjust rod extension and re-pin.
12. Repeat bleeding for other marker side.
JIC Torque Chart
Over-Torque Leak Risk:
Size Foot-Pounds N-m
tor>7
⁄
inator>16-20
11-12 15-16
1 ⁄
2
-20 15-16 20-22
tor>9
⁄
inator>16-18
18-20 24-28
tor>3
⁄
inator>4-16
38-42 52-58
tor>7
⁄
inator>8-14
57-62 77-85
tor>11
⁄
mina-
tor>16-12
79-87 108-119
Figure 82
Marker Cylinder Bleed
26247
1
3
2
1
2
3