Section V. BRAKE SYSTEM MAINTENANCE
5-12. BRAKEDRUM REPAIR.
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
(1) Remove hub, wheel bearings, and brakedrum (see paragraph 4-25).
(2) Ensure that the inside surface of the brakedrum is smooth, true, and concentric.
The maximum allowable eccentricity is 0.004 in. (0.10 mm) to prevent equipment damage.
(3) Ensure that the brakedrum is not bulged, bell mouthed, scored, or eccentric.
(4) If any of the above conditions exist, turn the brakedrum or replace them.
Each time brakedrums are turned, less metal remains to absorb the heat
developed by braking action. Brakedrums containing less metal will operate at
higher temperatures. As a result, brake fade, slow recovery, and erratic action will
be more noticeable. The extremely high temperatures will not only shorten lining
life but can also cause heat checks and cracks to form on the inner surfaces of
the brakedrums. These conditions will become progressively worse until the
(1) Use the correct size cone and mount the brakedrum on the lathe. Ensure that it is centered accurately.
(2) Turn the brakedrum. Take only light cuts and remove only enough material to clean up the brakedrum.
(3) Grind the finished surface. Use emery cloth on a straight board if a grinder is not available. Polish the
inside surface of the brakedrum.
(4) Clean brakedrums with steam or hot water. Do not use solvent.
(5) Brakedrums that do not need to be turned should be rubbed with emery cloth or fine sandpaper and
(6) Clean any metal particles or debris from inside the brakedrum before installing it.
(7) Install brakedrum, wheel bearings, and hub (see paragraph 4-25).
Section VI. FRAME AND TOWING ATTACHMENTS MAINTENANCE
5-13. LADDER MODIFICATION.
a. The following modification is at the discretion of the unit commander.
b. The fourth rung from bottom of ladder is close to the semitrailer body. Personnel can slip on this rung.