assembly removed (para 4-8), the brake shoes can
procedure on the other eccentric adjusting the
be removed, using brake spring pliers. Remove the
reverse shoe but turn the eccentric toward the rear
brake return spring by unhooking it from both
of the vehicle to bring the shoe against the drum.
shoes. Remove the locknuts and washers which
b. Brake Shoes--Major Adjustment Meth-
secure the anchor pins; from the rear of the brake
od. After brake shoes have been removed and
backing plate (fig. 1-5). Remove the anchor pin
replaced, the major brake shoe adjustment must be
plate and cams. Spread the shoes apart to clear the
made. Make the minor adjustment as outlined in a.
brake shoe strut and remove them.
above. Loosen the anchor pin locknuts and using
c. Remove Brake Assembly. Refer to paragraph
wrench (fig. 4-91, turn the anchor pins (fig. 1-5)
toward each other and down until the shoes are set
to 0.008-inch toe and 0.008-inch heel clearance as
Remove the cotter pins and clevis pins behind the
measured with feeler gages inserted between the
brake backing plate holding the cable end into the
shoe and the drum through the slot provided at the
brake lever. Loosen the brake cable clamps and
rim on the face of the drum. Tighten the anchor pin
pull the conduit portion of the cable assembly
lock nuts.
forward out of the clamp, compressing the spring.
When the conduit has cleared the clamp, slip the
cable adjustment should be preceded by the brake
cable out of the clamp opening. Remove the lock
shoe minor adjustment (a above). With the hand
nut and adjusting nut from the cable equalizer and
brake lever one-third of the distance from the fully
remove the equalizer. The cable will now slip out of
released position, loosen the lock nut holding the
the equalizer. Remove the bolts and nuts holding
cable equalizer and move the equalizer adjusting
the cable clamps to the frame cross member and
nuts forward or backward until a slight drag is felt
remove the clamps. Remove the cotter pin from the
at the wheels. Tighten the lock nut. The wheels
hand lever rod and lift the rod from the bellcrank.
must be free from drag with the hand lever in the
fully released position.
cotter pin and slotted nut from the bellcrank pivot
bolt and remove the bolt and bellcrank.
4-19. Maintenance
The parking brake should be inspected and
lubricated regularly according to the preventive
maintenance services outlined in table 4-1. Check
hand brake lever ratchet teeth for sharpness.
Replace ratchet if teeth are worn. Brake linings and
drums nust be kept free of dirt, oil, and grease and
the brake adjustments made (para 4-17). If in-
spection shows brake linings to be worn to the
extent that the rivets might come into contact with
the drum during the next period of service, a new
shoe assembly should be installed (para 4-20 c).
4-20. Installation
the ratchet segment against the rear of the hand
lever bracket so that the ratchet teeth are up and
the screw hole beneath the opening in the ratcte
lines up with the left hand hole in the bracket when
Figure 4-9. Brake adjustment with engineer's angle wrench.
facing the trailer from the front. Line up the hole at
4-18. Removal
the end of the ratchet with the right hand hole in
a. Remote Brake Hand Lever Assembly (fig. 1-
the bracket. Insert the 5 / 16-24 x 1 capscrew
1). Remove the cotter pin from the end of the rod
through the right hand holes in the bracket and
connecting the hand lever to the bellcrank and pull
ratchet. Assemble and tighten the 5 / 16-inch lock-
the rod away from the lever. Remove the safety nut
washer and 5 / 16-24 hex nut. Mount the hand
and capscrew holding the lever and the left side of
lever assembly so that it straddles the ratchet with
the ratchet to the hand lever bracket. The lever
the pawl release side of the lever assembly to the
assembly can now be pulled up free of the ratchet.
left. The lowest screw holes in the lever should now
remove the nut and lockwasher from the capscrew
line up with the holes in the left of the bracket and
holding the right side of the ratchet to the bracket.
Remove the capscrew and ratchet.
install and tighten the 3/8-24 hex safety nut. Insert
the end of the hand lever rod into the hole in the
wheel removed (para 4-2 b ) and the hub and drum
hand lever assembly just above the ratchet teeth.
4-11
