Hyundai r35z-7 Workshop Manual page 60

Dozer down operation
When the dozer down operation is carried out, the secondary pressure from the remote control
valve is applied to Pb1 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 B1 port through the load
check valve in the dozer section and the bridge passage since B1 port and the bridge passage
have been opened after the spool changeover and then into the head side of the dozer cylinder.
On the other hand, the oil returned from the rod side of the dozer cylinder flows into A1 port to the
tank passage that has opened with the spool's notch after the spool changeover.
Then, the dozer cylinder extends to lower the dozer.
To bridge passage
in dozer comp.
T1
To A1 port via
Cylinder rod side
Dozer
Boom swing
Swing
P3
P3
Supply
(connecting)
Dozer down operation
A1
2-28
B1
Spool changeover
direction
To cylinder head
side via B1 port
R35Z72MCV23
Pb1