Understanding Hydraulic Depth Control System (Series)

1. Master (control) cylinder (A) and wing (slave) cylinders (B-C) are connected in series.

2. As hydraulic oil is pumped into master cylinder base end, oil is forced out of cylinder rod end into first slave cylinder base end and from first slave cylinder rod end into second slave cylinder base end.

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

4. To compensate for smaller oil volume in master cylinder rod end, 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 slave cylinder.

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

N58905


A-Master (Control) Cylinder
B-Right-hand Wing (Slave) Cylinder
C-Left-hand Wing (Slave) Cylinder

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

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

8. After oil has rephased 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: Flexible fold machines are equipped with a pressure bleed-off circuit that bleeds off high-pressure oil to maintain consistent operating depth. When pressure by-pass hose is connected to open SCV, place SCV lever 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-Return Oil
B-Pressure Oil

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