Section II. HYDRAULIC SYSTEM

TM 55-1730-202-14

Note

(4) Remove the two screws (10) and chain

(11) from the pump pistor (9) and the pump

Tap each steel ball lightly with a brass drift as

body (18) and pull the piston out of the pump

they are installed to ensure proper seating.

body.

(4) Install the safaty valve assembly (32)

and the relief valve assembly (33) in the pump

(5) Remove the pump snap ring (8), pump

body.

wiper (7), pump packing wiper nut (6), backup

ring (12), and O-ring (13) from the pump

(5) Install the O-ring (13), backup ring

(12), pump-packing wiper nut (6), pump wiper

body.

(7), and pump snap ring (8) in the pump body.

(6) Remove the safety valve assembly (32)

Lubricate the pump piston lightly with hydraulic

and the relief valve assembly (33) from the

oil. slide the piston into the pump body. and

pump body.

tighten the wiper nut until a slight drag is felt

(7) Remove the plug (31) releasing the dis-

on the piston.

charge valve spring (24), intake vail e spring

(6) Install the chain (11) and two screws

(22), and two balls (21 and 23).

(10) on the pump body and the installed piston.

(7) Instill the elbow (34) in the pump body.

(8) Remove the two plugs (20) and the

(8) Install the piston pin roller (39) and

screen (19) from the pump body (18).

the pump piston pin (4) in the pump handle

(9) Remove the release assembly (38), ball

socket (2) and stake the pin in place. Position

(37), release stem packing nut (36), and the re-

the handle socket in the pump body and install

lease stem packing (35) from the pump body.

the pin assembly (15). Secure the chain (16) to

the pin assembly and the pump body with the

c. Cleaning, Inspection, and Repair.

two screws (14).

(1) Clean all parts and flush out all oil

(9) Secure the pump reservoir (26) and the

passages with cleaning solvent (Federal Specif-

pump body gasket (25) to the pump body (18)

ication P-D-680). Dry thoroughly with com-

with the six screws (5 and 17) and six lock-

pressed air and a lint-free cloth.

washers (3).

(2) Inspect the steel balls, pump piston pin,

(10) Install the vent assembly (29) and the

and the piston pin roller for pits and corrosion.

plug (27) in the reservoir. Insert the pump

Replace if defective.

handle (1) in the socket.

(3) Inpect the wiper nut, pump piston,

e. Adjustment.

and pump body for cracks, breaks, and distor-

(1) Screw the safety valve assembly down

tion. Check the clearance between the wiper nut

until the spring bottoms in the valve.

and the piston. Replace the wiper nut if the clear-

arce exceeds 0.008 inch. Check the clearance

(2) Install the reservoir as described in d

between the piston and the pump body. Replace

above and fill with oil (paragraph 8).

both parts if the clearance exceeds 0.011 inch.

(3) Place the pump in a holding fixture or

(4) Inspect all other parts for distortion

secure to a bench and attach a 5,000 psi pressure

and damaged threads. Replace if defective.

gage to the outlet at the bottom of the pump.

(5) Replace the O-ring, backup ring, and

(4) Tightly close the release valve and open

gasket.

the air vent at the top of the reservoir. Actuate

the handle to force fluid against pressure gage

(6) Replace a damaged screen.

to check setting of relief valve. Relief valve

d. Reassembly.

should actuate between 2,200 and 2,400 psi.

(1) Install the ball (37), release stem pack-

(5) Remove the pump from the reservoir

ing (35), release stem packing nut (36), and the

and set the safety valve to operate in a similar

release assembly (38) in the pump body (18).

manner at 1,950 to 2,150 psi.

(2) Install the screen (19) and two plugs

f. Installation. Install the pump assembly

(20), in the pump body (18)

(paragraph 39).

( 3 ) Install the ball (21), intake valve

g. Testing.

spring (22), ball (23), and discharge valve

(1) Set the jack up under a 5-ton load as

spring (24) in the pump body and retain by in-

directed in paragraphs 18 and 19.

stalling the plug (31).