TM-9-2350-238-20-2

CRANE (CAB) COMPONENTS RECOVERY VEHICLE, FULL TRACKED: LIGHT,ARMORED, M578

TECHNICAL MANUAL; UNIT MAINTENANCE MANUAL

MAY 1993

CHANGE 1

TM-9-2350-238-20-2 - Page 449 of 495

TM 9-2350-238-20- 2

F-15. BOOM CYLINDER HYDRAULIC SUBSYSTEM .

Functional Description .

a.

The hydraulic fluid power for th e

d.

Moving the handle of the directiona l

operation of the boom cylinders is supplie d

control valve (1) in the LOWER positio n

by the hydraulic power subsystem .

directs hydraulic fluid to the retract ports o f

the boom cylinders (4), which lowers th e

b.

The boom cylinder hydraulic sub -

boom. The relief valve (6) protects the sub-

system controls the power to raise an d

system from overpressure. Hydrauli c

lower the boom .

pressure passing through the flow contro l

valve (2) causes the relief valve (5) to ope n

c .

Moving the handle of the directiona l

and allow return flow to the reservoir .

control valve (1) in the RAISE positio n

directs hydraulic fluid through the bypass

e.

When the handle of the directiona l

check valve of the relief valve (5) to th e

control valve (1) is in the neutral position ,

extend ports of the boom cylinders (4) ,

hydraulic fluid is blocked, hydraulically lock-

which raises the boom. The relief valve (6)

ing the boom cylinders in a fixed position .

releases excess hydraulic fluid pressur e

The emergency release valve (7) can b e

over

2150

psi

(14,824

kPa)

to

return

to

opened to lower the boom .

the reservoir .

F-3 0