Hydraulic Circuit For Three Point Hydraulic System - Kubota L4400 Workshop Manual

L4400 , WSM
3. HYDRAULIC CIRCUIT FOR THREE POINT HYDRAULIC
SYSTEM
Hydraulic Oil Flow
1. When the engine (3) is started, the hydraulic pump (4) is rotated to draw oil from the transmission case (1) through
the suction pipe. Supplied oil is filtered by the hydraulic oil filter cartridge (2).
2. Filtered oil is forced out by the hydraulic pump to the front hydraulic block (6). When a front end loaders is equipped
with the tractor, oil pressure is taken from the front hydraulic block (6), and the return oil from the front end loader
flows back to this front hydraulic block (6), then into the position control valve (7) through the delivery pipe.
3. The position control valve (7) switches the oil to the hydraulic cylinder (9) for the three-point hydraulic system or
return to the oil tank (transmission case) (1).
• The hydraulic system has a relief valve (5) which restricts the maximum pressure in the circuit and a cylinder safety
valve which relieves shock presure in the hydraulic cylinder.
• When hydraulic power is taken out to use a hydraulically-operated implement, implementís cylinders can be
actuated by operating the double-acting auxiliary control valve (11).
Tractor Manuals Scotland - Please Do Not Copy
Tractor Manuals Scotland
8-M3
HYDRAULIC SYSTEM
(1) Oil Tank
(Transmission Case)
(2) Hydraulic Oil Filter Cartridge
(3) Engine
(4) Three Point System
Hydraulic Pump
(5) Relief Valve
(6) Front Hydraulic Block
(7) Position Control Valve
(8) Lowering Speed Adjusting
Valve
(9) Hydraulic Cylinder
(10) Hydraulic Cylinder Block
(11) Auxiliary Control Valve
(12) Cylinder Safety Valve
W1012963
KiSC issued 07, 2007 A