Assembly - TM-10-3930-618-340098

Replace spool if any land diameter is less than 0.748

NOTE

inch.

Do not attempt to remove all cuts as

(18) Clean deposits from balance orifice in

the face Will probably become out-of

spool using a fine, soft wire. Also check slow orifices

square with the outside diameter.

and clean as necessary using fine, soft wire.

CAUTION

(19) Check both springs (20 and 14) for bent or

Use care when honing to avoid

deformed condition. Spring (20) should have a free

breaking sharp edge between face of

length of 3 1/2 inches. Spring ( 14) should have a free

bushing and outside diameter.

length of 7/8 inch. Replace springs if bent, deformed, or

stretched.

(12) Measure entire bore of each bushing.

d. Assembly

Bores will be slightly oval due to wear but must not

(1) Reverse procedures in c above.

exceed 0. inch at any point or bushing must be

(2) Do not reuse packings and backup rings.

replaced.

(3) Apply small amount of heavy grease to

(13) Measure length of bushings at a number

packings (6) and backup rings (5) to hold them in

of points. Shortest length must not be less than 1.055

position on bushings (7). Slide bushings into bores, do

inch or bushing must be replaced.

not tap or force them in any way. Make sure packings

(14) Gears will sometimes make small cuts in

and backup rings remain in place. Apply a coat of light

rectangular land near flat of bushings. Depth of these

oil to bushing surfaces for ease of installation.

cuts must not exceed 0.002 inch or bushing must be

(4) Apply coat of light oil to gear faces and to

replaced.

shaft journals before installing.

(15) Inspect for erosion on bushing faces near

(5) Insert spring (20) in spool (21) and insert

rectangular lands and in lube oil slots. Erosion at these

spool in body bore. Assemble O -ring (22) to plug (23),

points is caused by air in oil. Replace bushings having

coat with light oil, and press plug into bore until flush with

erosion at these points. Slight erosion on outside

face of body. Then install flange (3) on body (18). Make

diameters and on flats is normal.

sure O -ring (4) is in place.

(16) Visually inspect spool (21) for erosion and

(6) Install relief valve parts ( 10 through 14) in

scratches. Insert spool in bore and check that it slides

order shown and tighten plug (15) until ii: bottoms.

freely in bore.

e. Installation. Refer to paragraph 2-10 for pump

(17) Measure diameters of spool lands.

installation.

4-2