TM 9-2330-203-14&P
4-20. SERVICE BRAKE ASSEMBLY REPLACEMENT (EARLY MODEL M197A1 AND M198A1) (Con't).
5.
Remove two anchor pins (10) from spider (11).
6.
Remove two adjusting screws (14) and gear (16) from spider (11).
7.
Remove retaining ring (19), washer (20), sleeve (21), and worm gear (18) from two adjusting studs (17). Remove
adjusting studs from spider (11). Discard washers and retaining rings.
8.
Remove two wheel cylinders (8) and shields (9) (para 4-23).
9.
Remove ten locknuts (13) and capscrews (22). Remove spider (11) and backing plate (12) from axle. Discard
locknuts.
b.
CLEANING AND INSPECTION
WARNING
DO NOT handle brake shoes, brake drums, or other brake components unless area has been
properly cleaned. There may be asbestos dust on these components which can be dangerous
if you touch it or breathe it. Wear an approved filter mask and gloves. Never use compressed
air or a dry brush to clean brake components. Dust may be removed using an Industrial-type
vacuum cleaner. Clean dust or mud away from brake components with water and a wet, soft
brush or cloth. Failure to follow this warning may result In serious illness or death to
personnel.
Dry cleaning solvent, P-D-680, Is toxic and flammable. Always wear protective goggles and
gloves, and use only In a well-ventilated area. Avoid contact with skin, eyes, and clothes, and
DO NOT breathe vapors. DO NOT use near open flame or excessive heat. The solvent's flash
point Is 100F-138F (38C-59C). If you become dizzy while using cleaning solvent,
Immediately get fresh air and medical help. If solvent contacts eyes, Immediately wash your
eyes and get medical aid.
1.
Clean all parts with dry cleaning solvent. Dry thoroughly.
2.
Inspect all parts for damage. Replace any damaged parts.
3.
Inspect brakeshoe surface for cracks, distortion, and excessive wear. Brakeshoe lining should have a minimum
thickness of ; in. (3.2 mm). Replace brakeshoe assembly if cracked of if lining thickness is less than Y in. (3.2 mm).
4.
Inspect brakeshoe lining rivets for looseness. Rivets should be at least .6 in. (1.6 mm) below surface of brakeshoe
lining. If rivets are less than 16 in. (1.6 mm) below surface of brakeshoe lining, replace brakeshoe assembly.
5.
Inspect worm gear and adjusting screw threads. File burrs from threads and chase defective threads on adjusting
screw.
c.
INSTALLATION
1.
Install backing plate (12) and spider (11) on axle using ten capscrews (22) and new locknuts (13).
2.
Install two wheel cylinders (8) and shields (9) (para 4-23).
3.
Install two adjusting studs (17) in spider (11). Install worm gear (18), sleeve (21), and new washer (20) on each
adjusting stud. Secure with new retaining ring (19).
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