Figure 4-2. Hydraulic Pump Assembly.

TM 55-4920-201-14

4-9. Hydraulic Pump Assembly. (See figure 4-2.)

limited by a piston stop washer and

The hydraulic pump assembly contains hydraulic

retaining ring (1). With the ram piston

fluid and is ready for use when removed from the

against this stop, further actuation of

balancing kit storage case and installed on the hoist

the pressure pump will result in a build-

arm structure of the stand assembly. Operation is as

up of internal pressure which may

follows:

cause damage to the load indicating

gage (8) or to internal pump parts.

a. To raise (hoist) a suspended load, turn the

Never operate the pump beyond an

pump valve (5) counterclockwise to the limit of its

indicated load of 800 pounds.

travel. This closes the ram bypass and directs

pressure to the ram cylinder. Actuate the pump

b. To lower a suspended load, turn the pump

handle (3) to raise the ram piston (6) to desired

valve clockwise to gradually open the ram bypass

level within the piston's normal travel of ap-

and unload the ram piston. For more rapid descent,

proximately 1 inches.

the valve may be turned clockwise as desired up to

the limit of its travel.

CAUTION

Upward travel of the ram piston is

Figure 4-2. Hydraulic Pump Assembly.

4-3