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(259)
BRAKES
ADJUSTMENTS
8-15
Throughout the adjustment procedure addi
-
tional
operations
are specified where inspec-
tion
indicates
their need. Each additional op-
eration is
identified
by an asterisk (*)
preced-
ing the reference to paragraph number cover-
ing the operation. The major brake adjustment
combined with required additional operations
constitute a general overhaul of the entire
brake mechanism.
1. Jack up car in a safe manner and remove
all
wheels.
2. Check fluid level in master cylinder reser-
voir and add fluid if
necessary (par.
8-8).
3. Check brake
pedal
for free action, proper
return to stop, and proper clearance at toe-
board (par. 8-11).
4.
Pump
brake
pedal a number of times with
quick r
eleas e.
If
pedal
develops a very solid
fe
el
and reduced travel, and brakes drag
heavily
when drums are turned, it indicates
that the compensating port in master cylinder
is blacked by a distorted piston primary cup.
If
brake pedal
goes slowly down when steady
pressure
is applied, and no leaks are found in
inspection
described later, it indicates a dis-
torted
primary cup or scored master cylinder
barrel.
Either condition required overhaul of
master
cylinder
(*par.
8-19).
5. Inspect all brake pipe and hose connec-
tions for
evid ence
of fluid leakage. See figure
8-1.
Tighten
any
leaking
connection, apply
heavy pressure
to brake pedal to build pres-
sure
in hydraulic system, and recheck connec-
tions.
6. Remove rear brake
drums,
and
front hub
and drum
assemblies.
NOTE: Since stops are
located
on
brake
backing plat
es
to
prevent
pis
-
ton
s
from
leaving w
heel cylind ers, it is not
necssary
to install
wheel cylinder clamps when
dru m s
are
removed;
how
ever, brake
pedal
must
not be operated while drums are re-
mov ed.
7. Clean all dirt out of
brake drums,
using
care to
avoid
getting dirt into
f
r ont
wheel
bearings.
Inspect
drums and replace or recon-
dition if required
(*par.
8-17).
8. Inspect front
wheel bearings
and oil seal
packings. Replace faulty
bearings
or packings
(*par.
6-14).
9. Blow all dirt from brake assemblies, then
inspect
brake linings for wear, oil soaking,
loose rivets, and imb
edded
foreign particles.
If
linings are worn nearly flush with rivets or are
oil soaked, replacement of linings is required
(*par. 8-16).
If
linings are otherwise service-
abl
e, tighten
or
r
eplace
loose ri
vets
and
thoroughly clean all steel or
other imbedded
particles from surfaces and
rivet
coun
ter-
bores of linings.
10.
Carefully pull lower edges
of wheel
cylinder boots away from cylinders and
note
whether
interior
is wet with brake fluid. Fluid
at this point indicates
leakage
past
the
piston
cup, requi
ring overhaul
of
wheel
cylinder
(*par.
8-18).
11.
Inspect
rear brake backing
plates
for oil
leaks past wheel
bearing
oil
seals. Correct any
oil leaks by installation of new
seals (*par.
5-9) .
12. Check all backing
plate
attaching bolts
to make
sure
they are tight. Check anchor
pin
nuts for tightness,
us
ing Wrench
J
854
(fig. 8-9).
13. Lubricate parking brake
cables,
para-
graph
8-14,
but leave cabl
e
adjusting nut
-ba cked off for adjustment later.
14.
If
brake sho
es
were not r
emoved
for
additional
work,
pry shoes away from backing
plates
and
clean
all rust and dirt
from
contact
surfaces on shoes and
plates,
using fine eme ry
cloth. Lubricate contact
surfaces
with a thin
coating of
Bendix
or Delco Brake Lubricant, or
Lubriplate. On rear brakes, sparingly apply
the same lubricant to parking
brake
strut and
backing plate boss
under the brake
ca ble.
15.
Lubricate front
wheel bearings,
install
hub and drum
assemblies
and adjust wheel
bearings
(par.
6-14)
.
16. Install rear brake drums and all four
wheels. Remove adjusting hole
covers
from all
backing plates.
17. Centralize brake shoes and set anchor
pins at
each
wheel as follows:
(a) Using Wrench J 854 (fig. 8-9), loosen
anchor pin nut just enough so that pin can
shift in slotted hole in backing plate.
If
nut
is loosened too much, the anchor pin will tilt
due to pull of brake shoe springs.
(b) Using Adjusting Tool J 1603-A
(fig.
8-
10), turn brake adj ust ing screw to expand
brake sho
es
until wheel can just be
turned
with two hands.
(c) Tap
anchor pin lightly to
make
sure it
centers
in the ends of brake 'shoes
while
they
are centered in the drum,
then tighten
anchor
pin nut
securely.
(d) Tightening the anchor pin nut should
not change the two hand drag previously ob-
tained.
If
it does, repeat the procedure with-
out loosening anchor pin nut quite as much.
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