Caution – Great Plains 2SNT30 Assembly Instructions User Manual
Page 16

4/9/04
1-14
113-395M
BLEEDING OF THE HYDRAULICS
1. Be sure tractor hydraulic reservoir if full.
2. With the marker(s) in field position, crack the hydraulic hose fitting(s) located at the base end of the cylinder(s). With
your tractor at an idle speed, activate your tractor hydraulic valve until hydraulic oil seeps out around the hose ends.
Tighten the hose end fittings and repeat this process with the hose end fitting(s) located at the rod end of the cylinder(s).
If dual markers are used with a selector/sequence valve, follow the procedure above for one marker cylinder. Then
crack the fittings on the back side of the selector/sequence valve, activate the tractor hydraulics valve until hydraulic oil
seeps out around the hose ends. Tighten the hose end fittings and repeat the complete process for the opposite marker
cylinder.
3. Fold and unfold the marker(s) slowly in order to work all the air out of your marker hydraulics. Use caution when fold-
ing and unfolding the marker for the first time, and check for pinching and kinking of hoses.
CAUTION!
NEVER ALLOW ANYONE NEAR THE DRILL WHEN CYCLING THE
MARKERS!
!
4. When the marker cylinder is equipped with a needle valve (#16) of Fig. 8 on page
1-8, screw the needle valve in to
adjust the marker speed to a low setting. Fold the marker up and down a few times and recheck for pinching and kinking
of hoses. With the tractor engine at an operating rpm, adjust the needle valve to limit the marker to a safe operating
speed. When markers are equipped with a selector/sequence valve, the valve has an internal orifice that regulates the
marker speed.
CAUTION!
EXCESSIVE FOLDING SPEEDS CAN CAUSE MARKER DAMAGE!
!
CAUTION!
ESCAPING FLUID UNDER PRESSURE CAN HAVE SUFFICIENT
FORCE TO PENETRATE THE SKIN. CHECK ALL HYDRAULIC LINES AND HOSES BE-
FORE APPLYING PRESSURE. FLUID ESCAPING FROM A VERY SMALL HOLE CAN BE
ALMOST INVISIBLE
.
USE PAPER OR CARDBOARD, NOT BODY PARTS, 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.
!
MARKER HYDRAULICS, GENERAL NOTES...
THE MARKERS CYCLE IN THE FOLLOWING SEQUENCE:
(1)
Right Up, Left Up
(2)
Right Down, Left Up
(3)
Right Up, Left Up
(4)
Right Up, Left Down
(5)
Sequence Repeats
To fold the wing boxes for transporting, position the handle on the selector/sequence valve towards the port marked "G".
Hydraulic oil is now diverted to the fold cylinders.
NOTE: Raising and lowering speed of the dual markers is regulated by an internal orifice in the sequence valve which
is sized for proper operation of the valve spool. DO NOT try to adjust or alter this orifice size. This will cause failure of
the sequence valve.
NOTE: 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 possible danger of cracking hydraulic fit-
tings from over tightening,
DO NOT
use plastic sealant tape.