Understanding Hydraulic Depth Control System-Series

NOTE: Series hydraulic system applies to Narrow FLEX-FOLD machines ONLY.

1. Center frame (control) #1 master cylinder (A) and #2 and #3 wing (slave) cylinders (B and C) are in series with each other.

2. As hydraulic oil is pumped into base end of master cylinder, oil is forced out of rod end and into base end of first right-hand wing (slave) cylinder (B). As this occurs, oil from rod end of first slave cylinder flows into base end of second left-hand (slave) cylinder (C).

3. Displaced oil from second slave cylinder rod end returns to tractor.

4. To compensate for smaller volume of oil in rod end of master cylinder, first slave cylinder is 6.4 mm (1/4 in.) smaller in diameter than master cylinder and second slave cylinder is 6.4 mm (1/4 in.) smaller in diameter than first.

5. As machine is raised and cylinders are completely extended, slave cylinders will become synchronized with master cylinder. This maintains uniform height across machine.

N58905


A-#1 Master Depth Control Cylinder
B-#2 Right-Hand Wing Depth Control Cylinder (Slave)
C-#3 Left-Hand Wing Depth Control Cylinder (Slave)

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6. Synchronization is accomplished by allowing pressure oil (A) to pass from base end of cylinder to rod end through a small orifice or rephase groove at rod end of each cylinder. When piston seal passes by orifice (cylinder fully extended), oil passes from BASE end of master cylinder to base end of slave cylinders. When slave cylinder rods are fully extended, return oil (B) passes from BASE end of slave cylinders back to tractor.

7. For synchronization to be accomplished, depth control must be held for a few seconds with cylinders fully extended to allow passage of oil through system.

8. After oil has "rephased" the system, leave depth control lever (or switch) in neutral position for at least three seconds to allow all cylinders to retract far enough to close rephase passages and completely synchronize system.

IMPORTANT: Narrow FLEX-FOLD machines are equipped with a pressure reduction circuit that bleeds off high pressure oil to maintain consistent operating depth. When pressure by-pass hose is connected to open SCV, place SCV control in "float" position for precise depth control. Float position opens a low pressure drain path to relieve pressure build-up off depth control circuit. (See OPERATING DEPTH CONSISTENCY for further information.)

N58906


A-Pressure Oil
B-Return Oil

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