Buick LeSabre 1965 Service Manual page 538

9 - 1 6 SERVICE
BRAKES
sure that cables operate rear
brake shoes freely and do not
bind. Check for free movement
of cable in brake cable equalizer.
On 49000, check idler lever r e -
turn spring for tension. Replace
a weak or broken spring. On 45,
46, 48000 Series, replace cable
assembly if spring is weak or
broken.
b. Brake Pedal Height and
Stop Light Switch
Adjustment
NOTE: Brake pedal height cannot
be adjusted in either manual or
power brake cars.
In both manual and power brake
cylinders, non-adjustable p u s h
rods connect directly to the brake
pedals. Therefore, brake pedal
height depends entirely on a stop
in the master cylinder, which is
also non-adjustable. No external
brake pedal return spring is used,
so pedal return depends entirely
on a spring within the cylinder.
Make certain that the brake pedal
returns completely when released
slowly. If the pedal does not r e -
turn freely, check all pivot points
for binding or lack of lubrication.
With pedal in fully released po-
sition, the stop light switch
plunger should be fully depressed
against an operating plate on the
pedal shank. Adjust switch by
turning in or out as necessary.
See Figures 9-15 and 16.
c. Initial Adjustment
at Wheels
1. Remove adjusting hole cover
from brake backing plate. Install
J-21281 through adjusting hole to
move actuator off adjusting screw.
Use J-6166 to turn brake adjust-
ing screw, expand brake shoes at
each wheel until the wheel can
just be turned by hand. Moving
end of tool in hand downward ex-
pands the shoes. See Figure 9-11.
The drag should be equal at all
wheels.
2. Back off brake adjusting screw
at each wheel 30 notches. If shoes
Figure 9-11—Expanding Brake Shoes
still drag lightly on drum, back
off adjusting screw one or two
additional notches. NOTE: Brakes
should be free of drag when screw
has been backed off approximately
12 notches. Heavy drag at this
point indicates tight parking brake
cables.
3. Install adjusting hole cover in
backing plate when adjustment is
completed.
4. Check parking brake adjust-
ment as described in paragraph
9-8.
5. Remove jacks and road test
car for service and parking brake
performance (par. 9-4).
9 - 8 PARKING BRAKE
ADJUSTMENT-
CABLE LUBRICATION
a. Adjustment
Adjustment of the parking brake
is necessary whenever the rear
brake cables have been discon-
nected or when the cables have
stretched due to extended use,
or if thicker linings have been
installed. On 49000 Series to in-
sure proper functioning of the
parking brake, the idler lever
must have approximately 3/8"
clearance in slot in frame as
shown in Figure 9-4 when park-
ing lever assembly is fully r e -
leased. Need for a parking brake
adjustment is indicated if the
service brake operates with a
good pedal reserve, but the park-
ing brake ratchets more than 8
clicks when depressed.
1. Make a brake adjustment as
described in paragraph 9-7 (sub-
par, c).
2. On 49000 Series check for cor-
rect position of idler lever in slot
in frame with parking brake fully
released. See Figure 9-4. If nec-
essary, adjust front cable clevis.
3. Depress parking brake pedal
exactly 3 ratchet clicks.
4. Tighten rear cable adjusting
nut until rear wheels can just be
turned forward using both hands
(heavy two-hand drag).
5. Release parking brake lever
and check both rear wheels to
make sure they turn freely in
either direction.
CAUTION: It is very important
that parking brake cables are not
adjusted too tightly to cause brake
drag. With automatic brake ad-
justers, a t i g h t cable causes
brake drag and also positions the
secondary brake shoe, hence the
adjuster lever, so that it con-
tinues to adjust to compensate
for wear caused by the drag.
The result is a cycle of wear
and adjustment that can wear out
linings very rapidly.
b. Cable Lubrication
49000 Series
Lubrication of parking cables is
not included in Lubricare Instruc-
tions (par. 1-1) since these cables
are usually lubricated during a
major brake adjustment. Vehicles
habitually operated under condi-
tions where mud and water are
frequently encountered may re-
quire more frequent lubrication
to insure free action and avoid
excessive wear of cables.
1. Disconnect rear brake cables
at equalizer and pull cables out
of frame tunnel and guides. See
Figures 9-3 and 9-4.