BART
2-2-BRAKE SYSTEM
2
-9
attained which is referred to as the
"run-out" of the power unit. Any
increase in hydraulic pressure he-
yond this point must be supplied
by physical effort of the driver.
NO POWER CONDITION
It should be noted that in case
of engine failure and consequent loss
of engine vacuum, at least one full
power brake application may be
made from the vacuum
in
the boost-
er. With the engine off and no vac-
uum in the power system, the brakes
can be applied in the conventional
manner by applying more physical
effort to the brake pedal.
PARKING BRAKES
An independent hand
-
operated
parking brake control actuates the
rear wheel brake shoes through a
cable linkage. The operating cable
is routed from the parking brake
control assembly to the equalizer
lever which is attached to the equal-
izer assembly. The rear brake cables
connect the equalizer assembly to the
parking brake lever at each rear
secondary shoe as shown in Fig.
1,
Part
3-1.
When the handle is pulled the pri-
mary and secondary brake shoes are
forced against the rear brake drums.
The handle is held in the applied
position by the engagement of a
spring loaded pawl with a ratchet.
Turning the handle counterclockwise
disengages the pawl from the ratchet
to release the brakes.
IN-CAR ADJUSTMENTS AND REPAIRS
BRAKE SHOE ADJUSTMENTS
Before installing the brake drum
The car should be in a raised posi-
tion with the wheels off the floor.
If
the car is raised on a frame-con-
tact hoist, disconnect the parking
brake cables to prevent the rear
brakes from being partially ap-
plied due to the rear axle and
spring sag on the hoist.
The hydraulic service brakes are
self-adjusting and require a manual
adjustment only after the brake shoes
have been relined, replaced, or when
the length of the adjusting screw has
been changed while performing some
other service operation.
The brake drums should be at
normal room temperature when ad-
justing the brake shoes. If the shoes
are adjusted when the drums are
hot and expanded, the shoes may
drag when the drums are cool and
contracted.
1.
After the shoes have been in-
stalled or the adjusting screw has
been turned, install the drum. Be
sure that all excess grease, oil, and
other foreign material are wiped off
the backing plate and drum.
FIG. 6-Adjusting
Brake Shoes
on the front wheel spindle, wipe
the spindle completely free of grease.
Install the drum carefully so that
the grease seal retainers within the
hub will not be damaged.
2.
Remove the adjusting hole cover
from the backing plate. Working
from the backing plate side, turn
the adjusting screw upward to ex-
pand the shoes (Fig.
6).
Expand
the shoes until a drag is felt when
the drum is rotated.
3.
Remove the drum.
Mark the
tooth on the star-wheel where the
adjusting lever contacts it. While
holding the adjusting lever out of
engagement with the adjusting screw,
back off the adjusting screw
%I
of a
turn with the fingers. If finger move-
ment will not turn the screw, free
it up; otherwise, the self-adjusting
lever will not turn the screw. Lu-
bricate the screw with a thin uni-
form coating of Stanolube
-
HD-
Moly Grease
-
Grade
2.
Any other adjustment procedure
may cause damage to the adjust-
ing screw with consequent self
adjuster problems.
4.
Apply a small quantity of high-
temperature grease to the points
where the shoes contact the backing
plate, being careful not to get the
lubricant on the linings. Install the
drum.
On front wheels, install the wheel
outer bearing, washer, and adjusting
nut, then adjust the wheel bearings
as outlined in Part
3-4,
Section
2.
On the rear wheels, install the
three Tinnerman nuts and tighten
securely.
5.
Install the wheel on the drum
and tighten the mounting nuts to
specification.
6.
Install the adjusting hole cover
on the brake backing plate.
7.
When adjusting the rear brake
shoes, check the parking brake cables
for proper adjustment. Make sure
that the equalizer lever operates
freely.
8.
After the brake shoes have been
properly adjusted, check the oper-
ation of the brakes.
FRONT BRAKE DRUM
REMOVAL
1.
Raise the car until the wheel
and tire clear the floor. Remove the
wheel cover or hub cap, and remove
the wheel and tire assembly from
the drum.
2.
If the brake drum will not come
off easily, insert a narrow screw-
driver through the brake adjusting
hole in the backing plate, and dis-
engage the adjusting lever from the
adjusting screw. While thus holding
the adjusting lever away from the ad-
justing screw, back off the adjusting
screw with the brake adjusting tool
shown in Fig.
7.
Back off the ad-
justment only if the drum cannot
be removed. Be very careful not
MOVE HANDLE
UPWARDS
HI 144-A
FIG. 7-Backing
Off
Brake Adjustment
To Next Page
Loading...
