Recement expander tube shields

TM 10-3930-242-34

installed to replace worn out linings. Replace all

distortion, and scored surfaces. Scored braked-

t w e l v e springs to insure uniform retraction.

rums can be repaired by turning on a lathe. No

brake lining is any better than the drum it con-

e. Reassembly. Refer to figure 5-7 and reas-

tacts. The maximum a brakedrum should be

s e m b l e the brake assembly as follows:

turned is 0.060 to 0.080 inch.

(1) Install two new O-rings (7) on expander

(9) If any linings have come loose from the

t u b e nozzle (5), lubricating them with vaseline,

s h o e s , re-rivet them.

and install inlet connectio-n (6).

(10) If the frame assembly is cracked or

b r o k e n , replace it.

CAUTION

( 1 1 ) Recement expander tube shields. If any

Be sure that the inlet connection opening

shields are loose, all shields should be removed

faces the vehicle, and that the inlet con-

and recemented, reversing the block and shoe

nection drum bolt clearance notch faces

a s s e m b l i e s from their original installation. Pro-

the wheel side of the torque plate.

c u r e a good neoprene base adhesive compound

a n d use per instructions.

(2) If the torque plate (8) has been removed

(a) Clean the shields with lacquer thinner

f r o m axle housing, install with opening at top.

or acetone. Do not use petroleum base solvents.

S l i d e expander tube (5) with inlet connection

(b) Place one shoe in the brake assembly.

o v e r the torque plate.

R e v e r s e the shoe to expose a clean section of

(3) Position lower half of frame (9) over ex-

tube, free from initial cement. Mark the position

pander tube and torque plate (8), and secure

of the extended end of the shoe on the tube.

with bolts (4). Tighten bolts 3/8 in. -38-42, in.

Note the position of the mark in relation to the

- 9 5 - 1 0 0 , 5 / 8 i n . -170-185

ft-lbs.

torque;

dry

t o r q u e bar of the frame assembly. Mark relative

thread.

p o s i t i o n s for the remaining shields.

(c) Coat cement on the tube at each of the

NOTE

twelve marks. Coat a spot 3 in. x 1 in. with the

If necessary to line up frame the bolt holes, start

1 - i n dimension being centered over the mark.

at one end and install five bolts; then install a

T h e 3-inch dimension should be centered bet-

c l a m p across the frame to line up the last two

w e e n the frames.

holes, and install these bolts.

(d) Coat the inside, or concave side, of the

(4) Position upper half of frame over expan-

s h i e l d s with cement. Keep cement confined to

der tube and torque plate, making sure that

the center 3 inches of the shields.

i n l e t connection lines up with frame cutout. In-

(e) Allow the cement to dry for 5 minutes.

s t a l l bolts. Tighten bolts 3/8 in. -38-42, i n .

(f) Place a shield on the tube so that one

-95-100, 5/8 in. - 1 7 0 - 1 8 5 f t - l b s . t o r q u e ; d r y

h a l f of the shield protrudes from under the end

thread.

of the shoe.

(5) Place a block and shoe assembly (2), be-

(g) Remove the shoe assembly and press

t w e e n the torque bars so that projecting end of

t h e shield firmly to the tube.

s h o e is approximately centered on a shield (3).

(h) Install the next shoe with a shield

P a r t i a l l y insert retracting spring (1) to tem-

c e n t e r e d under the protruding end of the shoe.

p o r a r i l y hold the lining assembly in place.

P r e s s the shield firmly to tube and install re-

(6) Dovetail a second block and shoe assem-

t r a c t i n g spring.

b l y into the first block and shoe, and partially

(i) Continue in the same manner with the

insert a second retracting spring. Drive the first

b a l a n c e of the shields, shoes and springs until

spring fully into position.

all brake shoes and shields are in place.

(7) Install the remaining block and shoe as-

(12) Replace expander tube if cracked,

s e m b l i e s in a similar manner, that is, always

c h a r r e d - o r if the nozzle is loose.

k e e p one shoe assembly ahead of the one in

(13) Replace brake lining if worn beyond the

w h i c h the retracting spring is being completely

minimum thickness if torque bar forms ridges

inserted.

on the end face of the linings that may cause the

f . Installation.

block and shoe assemblies to hang up, or if ex-

(1) Refer to figure 5-4 and reinstall the

c e s s i v e cracking or chipping is evident.

brake assembly.

( 1 4 ) Replace the frame assemblies if dis-

(2) Replace the wheel (TM 10-3930-242-12).

t o r t e d from any crack or damage.

g. Bleeding. Bleed the hydraulic brake system

( 1 5 ) Replace retracting springs if they are

(TM 10-3930-242-12).

b r o k e n or distorted, and when new linings are

5-20