Kubota WSM L3560, Workshop Manual

Page: 548 / 801

HYDRAULIC SYSTEM
L3560, L4060, L4760, L5060, L5460, L6060, WSM
8-M19
Roll-back
1. When the hydraulic control lever is set to the
"ROLL-BACK"
position, the spool (4) of the bucket control section
(2) moves to the left, which forms oil passages between passage 2 (8) and
B2
port, and between
A2
port and
T
port.
2. The pressure-fed oil from the
P
port flows to the neutral passage 2 (5) through the boom control section (1) and
PB
passage 1 (3). As the oil passage from the neutral passage 2 (5) to the
PB
passage 2 (6) is closed by the
spool (4), this oil opens the load check valve (7), and flows through the notched section of the spool (4) and
B2
port to retract the bucket cylinder (9).
3. Return oil from the bucket cylinder (9) flows to the transmission case through the
A2
port and
T
port.
9Y1210824HYM0022US0
(1) Boom Control Section
(2) Bucket Control Section
(3)
PB
Passage 1
(4) Spool
(5) Neutral Passage 2
(6)
PB
Passage 2
(7) Load Check Valve
(8) Passage 2
(9) Bucket Cylinder
P: Pump Port
T: Tank Port
PB: Power Beyond Port
A2: A2 Port
(From Bucket Cylinder)
B2: B2 Port
(To Bucket Cylinder)
a: Low Pressure
b: High Pressure
KiSC issued 03, 2016 A