3 - 2
Section H
9803/3280
Section H
3 - 2
Issue 1
Basic System Operation
A401110
LS
7
T
7
2 Wheel Steer Machines
Hydraulic Operation
The main components of the steering system are the priority
valve
7
, load sensing steer unit
42
, hydraulic tank
T
and the
front power track rod ram
10
.
When the steering wheel is turned, a pressure demand is
sensed at the priority valve
7
via load sensing line
LS
.
Oil from the hydraulic pump
P2
is then distributed via the
priority valve to the steer unit
42
, which then directs the oil
to the front power track rod ram
10
untill the required
steering lock is achieved.
When the steering lock is held, the pressure signal
LS
ceases, flow from the hydraulic pump
P2
is now distributed
to the main hydraulic circuit via the priority valve
7
.
Maximum steering system pressure is controlled by a relief
valve located in the steering unit
42
.
42
42
10
P2