Ford Thunderbird 1965 - Hydraulic System Service and Bleeding

PART
2-1
-GENERAL
BRAKE
SERVICE
25
MASTER
CYLINDER PUSH
ROD
ADJUSTMENT
The push
rod
is
designed with
a
self-locking
adjustment
screw
to
pro
vide the
correct
relationship
between
the
booster
piston and the master
cylinder
piston.
The
adjustment
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
re
quire
any
further attention
provid
ing
the push
rod
assembly
remains
in
the
original unit.
However,
when
a new
push
rod is used or
the
push
rod
assembly
is transferred to
an
other
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
di
mension
of
0.990-0.995
inch,
or
with
a
height
gauge as shown in Fig. 2.
The details
for
making
a height
gauge are
given in Fig.
3.
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 cyl
inder
to
the
power
section,
the piston
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
bubbles
appear,
the
port is open. If
the
primary
piston
cup
overlaps
the
compensating
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
system
has
been
disconnected
for
repair
or
replacement,
ajr
may
get
into
the
lines
and
cause
spongy
pedal
action.
Bleed
the
hydraulic
system
after it
has
been
properly
connected
ADJUSTMENT
SCREW
Push Rod
Gauge
#15
OR
#16 U.S.S. GAUG
E SHEET
H
STEEL
-
'
~
l3/4"
t
0.990"
0.995"
1
*1-1/16'S-
-%"*
H1087-C
H1086-A
FIG.
2
-Push
Rod
Adjustment
FIG.
3-Push Rod Guage
Dimensions
to be sure that
all air is
expelled
from the
brake
cylinders,
disc
brake
calipers,
and
lines.
The
hydraulic system
can
be
bled
manually
or
with pressure
bleeding
equipment.
With disc
brakes,
more
pumping
of
the
pedal is required
and
more
frequent
checking
of the
master
cylinder
may
be
necessary
while
bleeding.
Remove the
front
wheel and
tire
assemblies
in
order
to
gain
access
to the
bleeder
fittings
on the
disc
brake
calipers.
MANUAL
BLEEDING
Bleed
the
longest lines
first.
Keep
the
master
cylinder
reservoir
filled
with
new SAE
70R3-Wagner 2
IB
(301)
brake
fluid
during
the
bleeding
operation.
Never use
brake fluid
which
has
been drained
from the
hydraulic
system.
1.
Position
a
bent %-inch
box
wrench
on
the bleeder
fitting
on
the
right rear
brake wheel
cylinder
(Fig.
4). Attach a
rubber drain tube
to
the
bleeder
fitting.
The
end
of the
tube should fit
snugly
around the
bleeder fitting.
2.
Submerge
the free end of
the
tube in a
container
partially
filled
with clean
brake
fluid,
and loosen
the bleeder
fitting
approximately
Va
turn.
3.
Push
the
brake
pedal
down
slowly
thru its full travel. Close
the
bleeder
fitting,
then return
the
pedal
to
the
fully-released position.
Repeat
this operation
until air
bubbles
cease
to
appear at
the
submerged end of
the tube.
4.
When the
fluid
is
completely
free of
air
bubbles,
close the
bleeder
fitting
and remove
the
drain tube.
5. Repeat
this
procedure on
the
brake cylinders
or disc calipers
at
each
wheel in
order:
left
rear,
right
front,
and left front.
Refill
the
master
cylinder
reservoir
after
each
brake
cylinder is
bled
and
when
the
bleeding
operation
is
completed.
The
fluid
level
should
be
within
%
inch
of
the
top
of
the
reservoir.
The
diaphragm-type
gasket
should
be
properly
positioned
in
the
reservoir
cap
before
the
cap
is
installed.
6.
Be
sure
that
the
front
brake
pistons
are
returned
to
their
normal
positions
and
that
the
shoe
and
lin
ing
assemblies
are
properly
seated.
7.
Before
driving
the
car,
check
the
operation
of
the
brakes
and
be
sure
that a
firm
pedal
is
obtained.
PRESSURE
BLEEDING
Bleed the
longest lines
first.
Never
use
brake fluid
which
has
been
drained
from the
hydraulic
system.
The
bleeder
tank
should
contain
enough
new
heavy-duty
brake
fluid
to
complete
the
bleeding
operation,
and it
should
be
charged
with
10-30
pounds of
air
pressure.
1.
Clean
all
dirt
from
the
master
cylinder
reservoir cap.
2.
Remove
the
master
cylinder
reservoir
cap,
install
an
adapter
cap
to
the
reservoir,
and
attach
the
bleeder
tank hose
to
the
fitting
on
the
adapter
cap.
An
adapter
cap
can be
fabricated
by
cutting
a
hole
in the
center of a
reservoir
cap
and
soldering
a
fitting
at
the
hole.
The
adapter
cap
must be
securely
seated
and
completely
sealed
on
the
master
cylinder or
leakage
will
occur.
3.
Position a %-inch
box wrench
on the
bleeder
fitting
on
the
right
rear brake
wheel
cylinder
(Fig. 4).
Attach a rubber drain
tube to
the
bleeder fitting. The
end
of
the tube
should fit
snugly
around
the bleed
er fitting.
4.
Open the
valve on
the
bleeder
tank
to admit pressurized
brake fluid
to
the
master
cylinder
reservoir.
5. Submerge the
free
end of
the
tube
in
a container
partially
filled
with clean brake
fluid,
and
loosen
the
bleeder fitting.
6. When air
bubbles
cease
to
ap
pear in
the fluid
at
the
submerged
APPROXIMATELY
45'
HI
300
A
FIG.
4-Brake
Bleeder
Wrench