TM 5-3805-258-24-1
H Y D R A U L I C
S Y S T E M
S Y S T E M S O P E R A T I O N
SHUTTLE VALVE
The shuttle valve is part of the attachment hy-
draulic circuit. It is in the implement pilot system
between the sequence valve and the attachment
control valve. The shuttle valve is a double check
valve. Ball valve (4) opens the inlet passage with
the higher pressure and closes the inlet
the lower pressure.
passage with
SHUTTLE VALVE
1. Outlet paaaage to attachment valve spool. 2. Inlet
paaaage from open or raise stem of attachment pilot valve.
3. Inlet passage from sequence valve (close or lower stem).
4. Ball valve.
When the attachment control lever is moved
to OPEN or RAISE, position, pilot oil from the
open or raise stem of the attachment pilot valve
comes into inlet passage (2). The pressure of the
oil pushes ball valve (4) to the left which prevents
the flow of oil out of inlet passage (3) and permits
the flow of oil out of outlet passage (1). The pres-
sure oil from outlet passage (1) moves the attach-
ment valve spool to OPEN or RAISE position.
When the attachment control lever is moved to
CLOSE or LOWER position and the sequence
valve is activated, pilot oil from the close or lower
stem of the attachment pilot valve comes into inlet
passage (3). The pressure of the oil pushes ball
valve (4) to the right which prevents the flow of
oil out of inlet passage (2) and permits the flow
of oil out of the outlet passage (1). The pressure oil
from outlet passage (1) moves the attachment valve
spool to HOLD position.
3-102
