HYDRAULIC SYSTEM FOR STEERING
1. Line to tank. 2. Metering valve for steering. 3. Line to rod end of right cylinder and to head end of left cylinder. 4.
Line to head end of right cylinder and rod end of left cylinder. 5. Passage for pump oil. 6. Combination valve (relief and
pressure reduction valves). 7. Line for oil to the metering valve. 8 and 9. Relief valves (both in the same housing) for the
steering cylinders. 10. Passage for oil to tank. 11. Line to control valve for implements. 12. Line to control valve for
implements. 13. Steering cylinder on right side. 14. Steering cylinder on left side.
When the steering wheel is not being turned the oil in
lines (3) and (4), and in cylinders (13) and (14), can not
move and the front wheels stay in position. If the side of
one of the front wheels hits a restriction (material that will
not move), the positions of the front wheels twill move.
The force on the side of the wheel causes an increase in
the pressure of the oil in the cylinders and in one of the
lines to the cylinders. When the pressure of the oil in the
line gets to 1700 psi (119.5 kg'cm2), relief valve (8) or (9)
opens. The high pressure oil in the line goes through the
open relief valve and into the other line to the cylinders.
This lets the positions of the front wheels change.
The pressure setting of relief valves (8) and (9) can
be changed. For an increase in the pressure setting,
add shims in the plug over the spring in the valve.
Remove shims for a decrease in the pressure setting.
FRONT OF MOTOR GRADER
8 and 9. Plugs for relief valve. 13. Steering cylinder on