Refilling Hydraulic Pump Reservoir.

TM 55-4920-201-14

upper hole only, leaving lower screw installed in

necessary, refill to this level, using petroleum base

hydraulic fluid, Military Specification MIL-H-

arbor. In this case, repeat filling operation two or

5606.

three times at IO-minute intervals to insure small

air spaces are completely filled. Always insure that

e. Before reinstalling reservoir cover, pump

filler hole screws are carefully reinstalled following

ram piston to its full outward position and press it

filling or draining operation.

back to its full bottomed position several times.

Observe return flow of fluid into reservoir for

5-22. Refilling Hydraulic Pump Reservoir.

bubbles which would indicate entrapped air in

a. Remove pump positioning screw in end of

system. Repeat this process until no bubbles are

no. 6 hoist support tube, and remove pump

observed.

assembly from tube.

f. Reinstall reservoir cover, insuring that

b. Stand pump assembly on gage end, and

AN6230-3 seal is in proper position in cover

remove center screw from reservoir cover plate.

groove. Reinstall cover screw, insuring that its

Remove cover retaining ring.

AN6227-3 seal is in proper position. Reinstall

c. Replace center screw with no. 10-32 screw

pump assembly in no. 6 hoist support tube, and

(not furnished) having sufficient length to serve as

lock in position with pump positioning screw.

a puller handle, and remove reservoir cover plate.

NOTE

d. Press ram piston in to its full bottomed

Operation of the pump with the assembly

position (refer to section IV for operating in-

standing on the reservoir end will result in

structions), and observe fluid level in reservoir,

pumping air into the ramp pressure system

with pump standing on gage end. Fluid level, with

and consequent malfunction. Should this

ram fully bottomed, should be 1-1/4 to 1-3/8 inch

occur, repeat steps b through f.

below top edge of fluid reservoir. (See figure 5-2). If

5-5