Ford Thunderbird 1965 - Brake Adjustments and Common Repairs; Brake Booster System Troubleshooting

24
GROUP
2
-BRAKES
BOOSTER
DIAGNOSIS
GUIDE
BOOSTER
INOPERATIVE-
HARD
PEDAL
If
the
preliminary
tests
show
that
pair
or replace
parts
as necessary.
the
booster
is
inoperative
or
if a
If the
foregoing
procedure
does
hard pedal condition
still exists after
not
eliminate the
trouble,
remove
the
eliminating
the
causes
of "Excessive
booster
from the car.
Separate
the
Pedal
Effort"
or
"Hard
Pedal"
listed
front
shell
from the
rear
shell,
and
in Tables 1 and 2
the trouble
may
be
check the valve
and
rod
assembly
caused
by
vacuum
leakage.
Discon-
reaction
disc,
diaphragm
plates and
nect the vacuum line
at the
booster,
diaphragm
assemblies
for
damage
remove the vacuum
manifold and
that
would cause
leaks.
When
as-
check
valve
assembly,
and look
for
a
sembling,
be
sure
that the
diaphragm
sticking
or
faulty
check valve.
Check
assemblies are
properly
positioned.
all vacuum
connections
for
leakage Improper
location
could
cause
leak-
or obstruction.
Check
all
hoses for a
age
between
the
vacuum
and
atmos-
leaking
or collapsed
condition.
Re-
pheric
sides
of the
diaphragms.
BRAKES DRAG OR GRAB
If the brakes
still
drag
or grab
plunger
assembly.
Remove
and
dis-
after
eliminating
the
causes
listed in assemble the
booster.
Clean,
inspect,
Tables
1 and
2,
the
condition
is
and replace parts
as
necessary.
probably
caused
by
a
sticking
valve
SELF
APPLICATION
OF
BRAKES WHEN
ENGINE
STARTS
Remove
and disassemble
the
seated valve
poppet.
Clean,
inspect
booster.
Check for
a
leak in
the
and replace
parts
as
necessary. Be
rear shell.
Check the
diaphragms sure that the
diaphragms are
properly
for
being
out
of
locating
radii in the located
when assembling.
housing.
Check
for a
sticking
or
un-
COMMON
ADJUSTMENTS
AND
REPAIRS
PARKING BRAKE
LINKAGE
ADJUSTMENT
Check the
parking
brake cables
when
the brakes
are
fully
released.
If
the cables are
loose,
adjust them
as
follows:
1.
Fully
release the
parking
brake
pedal
by pushing
down
the manual
release
lever.
2. Raise
the
car.
3.
Adjust
the equalizer lever
against the
cable
spring
on
the
pedal
cable
to
the
dimension
shown
in
Fig. 1.
4.
Loosen the
adjusting
nut on
the
equalizer
rod,
and
then turn the
lock
nut
in
front
of
the
equalizer
several
turns
forward.
5.
Depress the
parking
brake pedal
1%
inches
from
its normal
released
position.
6.
While
turning
the
rear
wheels in
a
rearward
direction,
turn
the
ad
justing
nut
against
the
equalizer
until
a
moderate
drag
is
felt
(Fig.
1).
7.
When
the
cables are
properly
adjusted,
tighten the
locknut
against
the
equalizer.
8.
Release the
parking
brake,
and
check to make
sure that
the
brake
shoes
return to the
fully
released
position.
9. Depress the
parking
brake
pedal
two
inches.
Under normal
conditions,
this will
satisfactorily
hold
the
car.
U-CLIP
10.
Release the
parking
brake
again,
and
then depress
the pedal
Viinch.
The brakes
should not
drag
with the pedal
depressed Vz
inch.
If
the
rear
brakes do not
fully
re
lease,
check
the
cables
for kinks
or binds.
Free
the
cables
as
required.
LEVER-TO-CABLE
ADJUSTING NUT
EQUALIZER
LEVER
CABLES TO
REAR
WHEELS
H1307-A
FIG.
1
-Parking
Brake
Adjustments