b.
When all of the RCV lever (1) are set the neutral position, the spool (5) returns to right.
Then, the parking piston (15) is moved lower by spring force and the return oil from the
chamber G flows back to tank port.
At this time, the brake works.
16
15
1
RCV lever
2
Main control valve
5
Spool
8
Spring
15
Parking piston
16
Brake spring
Time delay valve
G
8
P3
2-60
5
SH
PG
1
2
140WF2SM37