Common Adjustments And Repairs; Parking Brake Adjustment - Ford Thunderbird 1966 Shop Manual

24
GROUP 2
-BRAKES
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
3/4 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
lock
nut 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.
10. Release
the
parking
brake
again,
and
then
depress
the
pedal
1/2
inch. The brakes
should not
drag
with
the
pedal
depressed 1/2 inch.
If
the
rear
brakes do
not
fully
release,
check
the
cables
for kinks
or
binds. Free
the
cables as
required.
MASTER CYLINDER PUSH
ROD ADJUSTMENT
The
push rod
is designed
with a
self-locking
adjustment screw
to
provide
the correct relationship
between the
booster
piston and
the
master
cylinder
piston.
The
ad
justment
screw
is
set
to the correct
height
at
the time
of original assembly
of
the
power
unit.
Under
normal
service
the adjustment screw
does
not
require any
further
attention
providing
the
push rod
assembly
re-
U-CLIP
CABLE HOUSING END
SPRING SEAT
CABLE SPRING
LEVER-TO-CABLE
ADJUSTING NUT
EQUALIZER
ROD
EQUALIZER LEVER
CABLES TO
REAR WHEELS
H1307-A
FIG. 1
Parking
Brake Adjustments
mains
in
the
original unit.
However,
when a new push rod
is
used or
the
push rod assembly
is
transferred to
another
unit,
the
distance from
the
end of
the
adjustment screw
to the
mounting
surface of
the
booster
body
should
be
rechecked either with a
micrometer
depth
gauge
to
a
dimen
sion
of
0.380 0.995 inch,
or with a
height
gauge as shown
in Fig. 2. The
details for making
a
height
gauge are
given
in Fig. 3.
ADJUSTMENT
SCREW
Push Rod
Gauge
HI
086-
A
FIG. 2
-Push
Rod Adjustment
#15 OR #16 U.S.S. GAUGE SHEET STEEL
2-7/8".
H1087-C
FIG. 3-Push
Rod Gouge
Dimensions
To
adjust
the
push rod,
hold
the
serrated end of
the
rod
with cross-
milled pliers and
turn the
adjustment
screw
in
to
shorten,
or out
to
lengthen.
After
assembly
of
the
master
cylinder
to the
power
section, the
pis
ton
cup
in
the
hydraulic
cylinder
should
just
clear
the
compensating
port
hole
when
the
unit
is in
the fully
released position.
This
can
be
checked
by
placing
a
few drops
of
brake fluid
over
the
compensating port and
ap
plying
light
air pressure
to the
output
port of the master cylinder.
If
air
bub
bles
appear,
the
port
is
open.
If
the
primary piston
cup
overlaps
the
com
pensating port,
there
will
be
no
flow
of air
through the
compensating
port.
If
this
condition
exists,
the
ad
justment
screw should
be
turned
into
the
push rod a slight amount or
until
the
compensating port
is
open.
HYDRAULIC SYSTEM BLEEDING
When any
part of
the
hydraulic
sys
tem
has been disconnected for
repair
or
replacement,
air
may
get
into
the
lines
and cause
spongy
pedal action.
Bleed
the
hydraulic
system after
it has
been
properly
connected
to
be
sure
that
all air
is
expelled
from
the
brake
cylinders,
disc brake
calipers,
and
lines.