Great Plains John Deere 750 20' Flat Fold Markers - Manual (Page 11)

3/20/2003 205-038M
9 Adjustments
Adjustments
Adjusting The Hydraulics
1. Be sure tractor hydraulic reservoir is full
2. Fold and unfold the marker(s) slowly in order
to work all the air out of your marker hydrau-
lics. Use caution when folding 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.
3. The marker hydraulic system is equipped with
needle valves to control how fast each marker
operates. The needle valves are built into the
sequence valve body. There are two hex ad-
justment heads, one for raising the markers,
and one for lowering the markers. These are
located on each end of the sequence valve.
To adjust the speed of each marker, screw the
needle valve clockwise to adjust the raise or
lower marker speed to a low setting. Fold the
marker up and down a few times and recheck
for pinching or collapsing of hoses. With the
tractor engine at an operating rpm, adjust the
needle valve to limit the marker to a safe op-
erating speed. 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 1fpbefore applying pressure. Fluid escaping
from a very small hole can be almost invisible. Use pa-
per or cardboard, not body parts, to check for suspect-
ed leaks. If injured, seek medical assistance form 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.
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
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 possi-
ble danger of cracking hydraulic fittings from over tightening
or valve contamination, DO NOT use sealant tape.