Hyundai r35z-7 Workshop Manual page 63

(10) SWING OPERATION
For the swing operation, both Pa pressurization and Pb pressurization are the same on operation so
that only Pa pressurization is explained as follows.
When the right swing operation is carried out, the secondary pressure from the remote control valve
is applied to Pa3 port to change over the swing spool.
Since the P3 side bypass passage is shut off at the swing section after the swing spool changeover,
the oil flowed from P3 port through the P3 side parallel passage flows into A3 port through the load
check valve in the swing section and the bridge passage since A3 port and the bridge passage
have been opened after the spool changeover and then into the swing motor.
On the other hand, the oil returned from the swing motor flows into B3 port to the tank passage that
has opened with the spool's notch after the spool changeover.
Then, the upper swing body swings right.
T1
Pa3
Spool changeover
direction
To swing motor
via A3 port
Dozer
To bridge passage
in swing comp.
Boom swing
Swing
P3
P3
Supply
(connecting)
Right swing operation
2-31
A3 B3
To B3 port via
swing motor
R35Z72MCV26