TM 9-2320-272-10
1-21.
HYDRAULIC SYSTEM OPERATION (Contd)
A
TRANSFER CASE POWER TAKEOFF (PTO) CONTROL - A manually operated control lever located inside the
cab that engages and disengages the transfer case power takeoff.
B
TRANSFER CASE POWER TAKEOFF (PTO) LINKAGE - Connects transfer case power takeoff control to
transfer case Power Takeoff (PTO).
C
TRANSFER CASE POWER TAKEOFF (PTO) - Receives driving power from vehicle’s engine through the transfer
case to provide mechanical driving power for the hydraulic pump.
D
POWER TAKEOFF (PTO) DRIVE SHAFT - Transmits mechanical driving power from the power takeoff to the
hydraulic pump.
E
HYDRAULIC PUMP - Draws oil from hydraulic oil reservoir and directs it to valves inside the crane control
console.
F
OIL FILTER - Filters used or bypassed oil from the control valve before it returns to the hydraulic oil reservoir.
G
HYDRAULIC OIL RESERVOIR - Storage tank for hydraulic oil.
H
SWIVEL VALVE - Permits oil to channel through pivot post while crane is swinging and eliminates twisting of the
hydraulic lines connecting reservoir to the stationary pump.
I
BOOM LIFT CYLINDER - A hydraulically-driven piston that extends upward when boom control lever is pulled
back to UP position, raising the boom. A check valve located near hydraulic oil inlet hose prevents piston from
lowering when control lever is in neutral. Oil returns through boom control valve back to hydraulic oil reservoir
allowing piston to lower when control lever is pushed forward to DOWN position.
J
BOOM HYDRAULIC LINES - Carry the hydraulic oil to and from boom lift cylinder. Oil pumped through the
bottom lines pushes the lift cylinder piston upward. Oil pumped through the top lines pushes the lift cylinder piston
downward. When this downward action occurs, the oil that originally pushes the cylinder upwards is returned to
the hydraulic oil reservoir.
K
BOOM CONTROL LEVER - Manual control attached to the control valve that determines hydraulic oil flow for
raising and lowering action of the boom. Lever is pulled back to raise the boom and pushed forward to lower
boom.
L
CRANE CONTROL CONSOLE - Houses BOOM, HOIST, CROWD, and SWING levers and their control valves.
M
BOOM CONTROL VALVE - Located directly below boom control lever. Valve directs hydraulic oil from the
hydraulic pump to the boom lift cylinder for lifting, or out of the lift cylinder and back to the hydraulic oil reservoir
for lowering.
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