Case 1470 Traction King Tractor Repair Manual

Manuals: Service Manual
General
Engine
Fuel System
Hydraulics
Steering
Power Train
Brakes
Electrical
Manual Extract: Depth Control Valve

With the depth control valve in slow-speed lifting position (approximately 1/8 inch rearward movement of the spool from the holding position), oil entering the valve’s inlet port passes thru a flow divider valve where it is divided into three passages. Oil flowing into the forward pas-sage is directed downward through the trigger valve needle and up thru the needle plug. A greater hydraulic pressure is applied to the lower end of the trigger valve than above it, moving the trigger valve upward and closing off the return oil passage.

Oil entering the middle passage from the flow-divider valve passes around the valve spool to the return port and is directed back to the reservoir. This reduces the oil volume available to the rear passage, thus limiting oil to the hitch cylinders. Oil entering the rear passage passes through the load check valve and out to the hitch cylinders. The lift action will continue until the hand lever is moved for-ward, or until the hitch relay shaft linkage moves the valve spool forward to its holding position.