Ford Thunderbird 1966 - Master Cylinder Procedures; Disassembly; Assembly

PART
2-2
-BRAKE
SYSTEM
2-21
diameter
surface
or
dust
boot
retaining
groove
of the
piston. Such
damage
causes poor
sealing.
H
1372
-
A
FIG.
20
Removing
or
Installing
Pistons
If
a
piston is
so
completely
seized
in
the cylinder
bore
that it can
not be re
moved with
the
special
tool,
force
the
cylinder
out of the
bore
by
positioning
two screwdrivers in
the piston
dust
boot
retaining
groove and
prying
out
ward.
To prevent
cocking,
tap
the end
of
the piston
lightly
around
the
cir
cumference with a
hammer,
while
the
prying
force
is
being
applied.
Be
careful to avoid
damaging
the
dust
boot
retainer
in
the
caliper
housing
(Fig.
21). If this
method
of
removal is
used,
the pistons must be replaced.
If the
caliper dust boot retainer or
retaining
groove is damaged
or
scratched,
pry
the
retainer out of the
caliper
housing
with
screwdrivers.
9.
Remove
the
rubber
piston
seals
from
the
grooves
in the
cylinder
bores
by
carefully
inserting
the point
of a
small
knife
or
other pointed
in
strument
under the
seal and
raising
the
seal
up
far
enough to
be pulled
out
with
the
fingers.
CLEANING
AND
INSPECTION
Clean
all
metal parts with alcohol
or
a
suitable solvent
(Fig. 21).
Use
clean,
dry,
compressed
air
to clean
out
and
dry
the
grooves
and
passage
ways. Be
sure that
the
caliper
bore
and
component
parts are
completely
free of
any
foreign
material.
Check the cylinder bores and
pis
tons for damage or
excessive
wear.
Replace
the
piston if
it
is
pitted,
scored,
or the
chrome
plating
is
worn
off. Check the
caliper dust
boot
retainer for wear or
damage.
ASSEMBLY
1.
Clamp
the
caliper
in a vise
and
secure it
by
the
mounting
flange on
the
inboard housing.
2. If
a
new caliper
dust boot
retainer
is to be
installed,
thoroughly
clean
the
contact area on the caliper
housing
and
apply
Loctite
Sealant,
Grade H to the
retainer surface
that
seats in
the housing. Install
the
retainer in
the caliper
housing.
3.
Apply
a film of clean brake
fluid
to
new
caliper piston
seals
and
install
them in
the
grooves of the cylinder
bore.
The seal
should be positioned
at
one area in
the
groove and
gently
worked around.
Do not
use the
orig
inal seals.
4.
Coat the
outside
diameter
of
the
pistons with
brake fluid
and
install
them in
the cylinder
bores so that the
open
end
of
the
piston and
the boot
retaining
groove
face
out
of
the
bore.
To
avoid
cocking,
locate
the
piston
squarely
in
the
bore
and
apply
a
slow
steady
pressure.
If a
piston
will
not
easily
go
all the
way
into
the
bore,
re
move it
and
thoroughly
inspect
the
cylinder
bore,
the
piston
seal
and
the
installation
of the
seal.
If the
piston
still
will not go
in
with
bore
in
good
condition and
the
piston
seal
properly
installed,
use
the
tool
shown
in
Fig.
20.
Rotate
the
piston
with
the
tool
while
pushing
it
inward at
the
same
time.
5.
Carefully
install
four
new dust
boots on
the
caliper
housings
and
pis
tons. Be
sure that
each
boot is
fully
seated
in the
groove
of its
respective
caliper
housing
and
piston (Fig.
21).
Do not use
the original
dust
boots.
6.
Install
the
external transfer tube.
7. Install the flexible brake
hose to
the caliper.
8.
Install the caliper
assembly
on
the
spindle,
and
install
the shoe and
lining
assemblies and
the splash
shield
as
outlined
in Section 2.
9. Check
the caliper for
fluid leaks
under
maximum
pedal
pressures. Do
not move the
car until a firm
brake
pedal is
obtained.
CALIPER
ABUTMENTS
outboard caliper
housing
DUST BOOT
RETAINING
GROOVE
o
^>
PISTON
SEAL
(4)
EXTERNAL
TRANSFER
TUBE
INBOARD CALIPER HOUSING
^
DUST
BOOT
(4)
SPLASH
SHIELD
SHOE AND
LINING
ASSEMBLIES
FLEXIBLE
HOSE
H1367-B
FIG.
21
Caliper
Assembly
Exploded
View