4-56. SERVICE BRAKE MAINTENANCE (DUAL WHEEL CYLINDERS) (Con't).
CLEANING AND INSPECTION I
DO NOT handle brakeshoes, brakedrums, 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 100 F-138F (38 C-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.
Clean all parts with dry cleaning solvent and dry
Inspect all parts for cracks, breaks, corrosion, or
other damage. Replace all damaged parts.
Inspect pins (22) for damage. Replace if dam-
Inspect brakeshoe linings (23) for cracks, distor-
tion, and excessive wear. Replace brakeshoes if
damaged or worn.
Measure depth of rivets (24) below brakeshoe
lining (23). Replace brakeshoe if depth of rivets is
less than 3/32 in. (2.38 mm) below brakeshoe
Inspect braking surface for grease or hydraulic
fluid. If grease or hydraulic fluid is present, replace
If replacing brakeshoes only, perform steps 6
Install dust shield (11) and backing plate (5) on axle (12) using ten screws (14) and new locknuts (13).
Install two anchor pins (10) in backing plate (5).
Install two adjusting screws (21) and gears (15) in backing plate (5).
Install new keywasher (17) on each stud (18). Install two studs, worm gears (20), and sleeve bushings (19) in
backing plate (5). Secure with two new retaining rings (1 6).