TM 5-4930-244-14
(7)
Vent trailer air brake system pressure by opening drain valve. Close drain valve after all pressure is released
(para. 4-51).
b.
Disassembly.
(1)
Dislodge bearing cap (7) from hub and drum (3) by working around the outer circumference of the bearing cap (7)
with a hammer and chisel.
(2)
Remove the cotter pin (8) from spindle (9) and discard it.
(3)
Unscrew spindle nut (10) and bearing washer (11) from spindle (9).
(4)
Pull the hub and drum (3) out slightly, then push it back into its original position. This should force the outer
bearing (12) off the spindle (9) enough so it can be removed.
NOTE
If drum does not come off the spindle, release tension on brake shoes.
(5)
Remove rubber plug from brake back plate inspection hole and insert screw driver and brake tool through
inspection hole. Back off the brake adjustment screw with a screw driver and brake tool while holding the brake
adjusting lever away from the wheel until the brake shoes are just slightly a drag on the hub and drum (3). The
hub and drum (3) must still be able to rotate freely.
(6)
Pull the hub and drum (3) off the spindle (9).
NOTE
As this is done, note how the grease seal is installed.
(7)
Use a screwdriver to pry the grease seal (14) out of the rear of the hub and drum (3).
(8)
Remove the inner bearing (15) from the hub and drum (3). Wrap inner and outer bearings (12 and 15) in oil proof
paper if parts are not to be used right away.
(9)
If bearings (12 and 15) are being replaced, use a puller to remove outer and inner bearing cups (13 and 16) from
hub and drum (3).
c.
Repair.
WARNING
Dry cleaning solvent is flammable and toxic. Keep solvent away from open flames
or sparks. Avoid inhaling solvent fumes. Avoid contact with skin.
CAUTION
Bearings must not be dried or spun with compressed air. See TM9-213, Inspection,
Care and Maintenance of Anti-friction Bearings, for care and maintenance of
bearings.
(1)
Use dry cleaning solvent to remove all traces of the old grease from the bearings (12 and 15), hub and drum (3)
and spindle (9). A small brush may prove helpful; however make sure no bristles from the brush embed
themselves inside the bearing rollers. Allow the pair to air dry.
4-184
