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
ATTACHMENT PILOT VALVE
(Close or Lower Stem in CLOSE or LOWER Position)
OPEN or RAISE Position
When the attachment control lever is moved to
OPEN or RAISE position, actuator (1) moves in a
clockwise direction. The movement of the plunger
and stem in the attachment pilot valve is the same as
in RAISE position of the lift and tilt pilot valve. Open
or raise stem (14) moves down and oil from pump
passage (13) goes through holes (12). The oil goes
out passage (17) to one end of the attachment valve
spool. The attachment valve spool moves into OPEN
or RAISE position.
The oil from the chamber at the opposite end of the
attachment valve spool comes back through passage
(16). This oil goes through holes (11) of close or
lower stem (15) into tank passage (6).
CLOSE or LOWER Position
When the attachment control lever is moved to
CLOSE or LOWER position, actuator (1) moves in
a counterclockwise direction. The movement of the
plunger and stem in the attachment pilot valve is the
same as in LOWER operation of the lift and tilt pilot
valve. Close or lower stem (15) moves down and oil
from pump passage (13) goes through holes (11).
The oil goes out passage (16) to one end of the
attachment valve spool. The attachment valve spool
moves to CLOSE or LOWER position.
The oil from the chamber at the opposite end of the
attachment valve spool comes back through passage
(17). The oil goes through holes (12) of open or raise
stem (14) into tank passage (6).
1. Actuetor. 2. Plunger. 3. Plunger. 4. Retainer. 5. Re-
tainer. 6. Tank paasage. 7. Metering spring. 6. Metering
spring. 9. Centering spring. 10. Cantaring spring. 11.
Holas. 12. Holes. 13. Pump (supply) passage. 14. Open or
raisa stem. 15. Close or lower stem. 16. Passage to at-
tachment valve spool. 17. Passage to attachment valve
spool.
3-100
