Kubota WSM L3540-II, Workshop Manual

Page: 463 / 672

HYDRAULIC SYSTEM L3540-II, L4240-II, L5040-II, L5240-II, L5740-II , WSM
8-M20
Dump
1. When the hydraulic control lever is set to the "DUMP" position, the spool (3) of the bucket control section (2)
moves to the right, which forms oil passages between passage 2 (9) and A2 port, also between B2 port and T port.
2. The pressurized oil from the P port flows to the neutral passage 2 (10) through the boom control section (1) and
PB passage 1 (5).
As the oil passage from the neutral passage 2 (10) to the PB passage 2 (6) is closed by the spool (3), this oil
opens the load check valve (7) and flows through the notched section of the spool (3) and A2 port to extend the
bucket cylinder (11).
3. Return oil from the bucket cylinder (11) flows to the transmission case through the B2 port and T port.
9Y1211167HYM0023US0
(1) Boom Control Section
(2) Bucket Control Section
(3) Spool for Bucket Control
(4) Spool for Boom Control
(5)
PB Passage 1
(6) PB Passage 2
(7) Load Check Valve
(8) Relief Valve
(9) Passage 2
(10) Neutral Passage 2
(11) Bucket Cylinder
(12) Detent Mechanism P: Pump Port
T: Tank Port
A1: A1 Port
A2: A2 Port
B1: B1 Port
B2: B2 Port
PB: Power Beyond Port
(a) Low Pressure
(b) High Pressure
KiSC issued 02, 2015 A