Hyundai r35z-7 Workshop Manual page 59

8) DOZER OPERATION
Dozer up operation
When the dozer up operation is carried out, the secondary pressure from the remote control valve is
applied to Pa1 port to change over the dozer spool.
Since the P3 side bypass passage is shut off at the dozer section after the dozer spool changeover,
the oil flowed from P3 port through the P3 side parallel passage flows into A1 port through the load
check valve in the dozer section and the bridge passage since A1 port and the bridge passage
have been opened after the spool changeover and then into the rod side of the dozer cylinder.
On the other hand, the oil returned from the head side of the dozer cylinder flows into B1 port to the
tank passage that has opened after the spool changeover.
Then, the dozer cylinder retracts to raise the dozer.
T1
Pa1
Spool changeover
direction
To cylinder rod
side via A1 port
To bridge passage
in dozer comp.
Dozer
Boom swing
Swing
P3
P3
Supply
(connecting)
Dozer up operation
A1
2-27
B1
To B1 port via
Cylinder head side
R35Z72MCV22