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9803/
3280
Issue
1
Steer Unit Operation
- 4 Wheel Steer Machines
4 Wheel Steer Mode
- Neutral
Flow from the priority valve enters the steering unit
through the bottom right hand port past the non-
ret urn valve
43C
. When t he st eering w heel is
stationary the inner spool
A
and sleeve
B
are held
in the neutral position by the centring springs
K
. As
the unit is 'closed centre' the flow from the pump is
dead ended by the steering unit.
Component Key:
A
Inner Spool
B
Sleeve
D
Stator
K
Centring Springs
X
Steer Mode Control Valve
43C
Non-Return Valve
In 4 wheel steer mode the spools of the steer mode
control valve
X
are configured as shown.
4 -
2
4 -
2
Cir
c
uit
D
e
sc
rip
tio
ns
S
e
c
tio
n H
S
e
c
tio
n H
A395730