1977 DATSUN PICK-UP brake

f

BR317

Fig
BR
23

Gre
ing
point

4

Tightening

torque

Wheel

cylinder

J
S
to
1

8

kg
m

II
to

13ft
Ib

Connector
bolt

1

9
to
2
5

kg
m

14
to
18
ft
Ib

Brake
tube

1
5
to
1

8

kg
m

II

to
13

ft
Ib

Air
bleeder

0
7
to
0
9

kg
m

S

to
7
ft
Ib

Brake
disc

5
4

to
6
4

kg
m

39
to
46
ft

Ib

S

Adjust
brake
shoe
clearance
and

bleed
brake

system
Upon
completion

of

the
above

adjustments
make
sure

that
brake

operates
correctly
and
no

brake
fluid
leaks

MASTER
VAC

DESCRIPTION

A
vacuum

suspended
Master
Vac

is

installed
behind
the

master

cylinder

As
the

brake

pedal
is

depressed
fluid

is

forced
under

high
pressure
through

the
brake

pipes
to
the
wheel

cylinders

to
retard

or

stop
the

vehicle

The
Master
Vac
contains

a

spring

loaded

diaphragm
of
IS2
4

mm
6
in

in

diameter
It

operates
on

negative

pressure

produced
n
the

engine
intake

manifold

The
tandem

master

cylinder
is

capable
of

producing
high
pressure

even
if
the
Master
Vac
is

faulty
Brake

System

Note
The
Master
Vac

diaphragm
dif

fers
from
fonner
ones
for

improved

braking
force
Do
not
install
fonner

Master
Vac
on
1976
models
The

1

Plate
and
seal

2
Push
rod

3

Diaphragm

4

Rear
shell

5

Diaphragm

plate
Master
Vacs

are
identified

by
the

label
color
as
follows

1976
model
Caution

Label

Former
models
YeJlow

BR321

11

Valve

operating
rod

12
Valve

return

spring

13

Poppet
return

spring

14
Exhaust
valve

15
Valve

plunger

16
Reaction

disc

17

Diaphragm
return

spring

18
Front
shell
6
Seal

7

Vacuum
valve

8

Poppet
assembly

9
Valve

body
guard

10
Air

silencer
filter

INSPECTION
OF

OPERATION

Checking
yscuum

pressure

I
Connect

a
vacuum

gauge
in
the

line
between
check
valve

and
Master

2
Start

engine
and
increase

engine

speed
Stop
engine
when
vacuum

gauge
indicates
SOO

mmHg
19
69

inHg

BR
14
Fig
BR
24
Sectionall1iew

of
Master
Vac

Vac
as

shown
in

Figure
BR
25

1

Check
valve

2

Vacuum

gauge

BA169

Fig
BR

25
Air

tight
t
t
t

up

Air

tight
test

I
Fifteen

seconds
after

engine
is

stopped
observe
the

rate
of

drop
in
air

pressure
registered
by
vacuum

gauge

If
a

pressure
drop
of
25

mmHg
0
98

inHg
is

exceeded
refer
to
the
follow

ing
chart
to
determine
the
cause
of

failure

Probable
cause

I
Air

leakago
at
check
valve

2
Air

leakage
a

t

push
rod
seal

3

Air
leakage
between
valve

body
and

seal

4
Air

leakage
at
valve

plunger
seat

5

Damaged
piping
or

joints

2
Fifteen

seconds
after

engine
is

stopped
and
brake

fully
applied
ob

serve
the

rate
of

drop
in
air

pressure

registered
by
vacuum

gauge

Probable
cause

1
Air

leakage
at
check
valve

2

Damaged
diaphragm

3
Reaction
disc

dropped
off

4
Air

leakage
at

and
valve
body
poppet
assembly
seat

Note
When

replacement
of

any
part

is

required
be
sure
to
renew

Master

Vac
as
an

assembly

Inspecting
check
valve

Remove

clip
and
disconnect
hoses

at
connections

The
check
valve

can

now
be
removed

yr

BA3

Fig
BR
26
Location

of
check
valve

2

Using
a
Master

Vac
tester

apply
a

vacuum

pressure
of

200

mmHg
7
87

inHg
to

the

port
of
check

valve
on
the

Master
Vac
side
If
a

pressure
drop
of

10

mmHg
0
39

inHg
is
exceeded
in
1

I

I

17
I

f
I

I
I

Z
I

I
y1
I

I
I
7
I
I
I

I
I
I

I
I
I

I

y1
II

I

I
I
I
I
I

I
L
I
L

5
to
15

20
25
30
35
40

45
50

55
60

22
44

66

88
110
132

Pedal

operating
force

kg
lb
BR772

Fig
BR
28

Performance
curves

of
Master
Vac
Brake

System

Corrective
action

Replace
check
valve

Replace
seal

Repair
or

replace
faulty

partes

Repair
or

replace
seat

Repair
or

replace

If
a

pressure
drop
of
25

mmHg

0

98

inHg
is

exceeded
refer
to

the

following
chart
to
determine
the
cause

of

failure

Corrective
action

Replace
check
valve

Replace

Reinstall
and
check

push
rod

for

proper
turn

Replace

faulty
part
s

15
seconds

replace
check
valve
with
a

new
one

3
When

pressure
is

applied
to
the

Master
Vac
side
of
check

valve
and

valve
does
not

open
replace
check

valve
with
a

new
one

120
I

7IG

110
1
560

100

I
420

i
90
1
280

I

u

80
1
140

70
1
000

II

60
850

0

0

5

a
50
710

40
570

30
430

20
280

10
140

BR
15
1

I

Manifold

side

Master

Yac
side

1

Spring
2

Valve

BA289

Fig
BR

27
Sectional
view

of
check

valve

Operating
test

1
Connect

an
oil

pressure
gauge
in

brake
line

at
connection
on
master

cylinder

2
Install
a

spring
scale
on
brake

pedal

3

Start

engine
and
increase

engine

speed
until

a
vacuum

pressure
of
500

mmHg
19
69

inHg
is

registered
on

vacuum

pressure

gauge
With
a

vacuum

pressure
of
500

mmHg
19
69

inHg

held

measure
an
oil

pressure
with

respect
to

each

pedal

operating
force

Relationship
between
oil

pressure

and

pedal

operating
force
is
illustrated

in

Figure
BR
28
If

test
results
are
not

as

specified
in

Figure
BR
28
check

Master
Vac
for
condition
in

a
manner

as
described
under

Inspection
before

removal
of
this
unit

Also
check
brake
line
for
evidence

of
fluid

leakage

Note
Determine
whether
malfunc

tion
occurs
in
Master
Vac
or
in

check
valve

Always
inspect
check

valve
fiTlit

REMOVAL

Referring
to

Figure
BR
29

remove

parts
in
numerical
order

enumerated

1

cD
2

BR17S

Fig
BR
29
Removal
method

of

Mcuter
Vae

DISASSEMBLY

When

disassembling
Master
Vac

ob

serve
the

following
instructions

a

Thoroughly
clean
mud
or
dust
from

Master
Vac

b
Extreme

care
should
be
taken
not

to
allow
dirt
dust
water
or

any

other

foreign
matter
into

any
com

ponent
parts

Be

sure
to

select
a
clean

place

before

disassembly
or
assembly

c
Mark

mating
joints
so
that

they

may
be
installed

exactly
in
their

original

positions

d

Keep
all
disassembled

parts

arranged
properly
so
that

they
may

readily
be
assembled

at

any
time

e
Clean
rubber

parts
and

synthetic

resin

parts
in

alcohol

f
Mter
all
disassembled

parts
are

cleaned
in
a

suitable
clean
solvent

place
on
a
clean
work
bench
Use

care
not
to
allow

dirt
and

dust
to

come
into

contact
with
these

parts

1
Install

spacer
on

rear
shell

spacer

temporarily
Place
Master
Vac
in
a

vise
Use
soft

jaws

2

Remove
clevis
and
lock
nut
De

tach
valve

body

guard

rW

ID

1

Clevis

2
Lock

nut
3
Valve

body

guard

BRD7S

Fig
BR

30

Removing
rear
hell
Brake

System

3

Identify
front
shell
and

rear
shell

clearly
so
that

they
may
be
reassem

bled
in
their

original

positions
from

which

they
were
withdrawn

Bolts

attached
on
dashboard
are

not
the

same
in

pitch

4

Using
Master
Vac
Wrench

ST08080000
remove
rear
shell
seal

assembly
and
disassemble

diaphragm

plate
assembly
front
shell

assembly

diaphragm
spring
and

push
rod

assem

bly

f

Q
BA076

Fig
BR
31

Removing
reor
shell

Rear
shell
seal

Pry
off
retainer
with

use
of

screw

driver

as
shown
and

detach

bearing

and
seal

Note
Do

not
disassemble
seal
assem

bly
unless

absolutely
necessary

Whenever
this
is
to
be

removed
use

care
not
to

damage
it

BRD7S

Fig
BR
32

Removing
retainer

Diaphragm
plate

Place

diaphragm
plate
assembly

on

a
clean
work
bench
Detach
dia

phragm
from

groove
in

plate
as
shown

BR
16
BA079

FlIf
BR

33

Separating

diaphragm

2

Using
a
screwdriver

as
shown

evenly
pry
air
silencer
retainer

until
it

is
detached
from

diaphragm
plate
as

sembly

Note
Never

use
a

hammer
to

remove

this
retainer
since
this
win
be
the

sure

y
of

damaging
it

BA322

Fig
BR
34

Removing
air
silencer

retainer

3
Pull

out
valve

plunger

stop
key

and
withdraw
silencer
and

plunger

assembly

Note
To

remove
valve

plunger

stop

key

properly
proceed
as

follows

With

key
hole

facing
down

lightly

push
valve

operating
rod
simulta

neously
while

applying
vibration
to

it

BA180

Fig
BR
35

Pulling
out

top
key

BA1Bl

Fig
BR
36

Remouing
ualue

operating

rod

assembly

4

Withdraw
reaction

disc

BA286

Fig
BR
37

Remouing
reaction
disc

Front

shell
seal

I

Detach

flange
from

front
shell

assembly

BR287
g

Fig
BR
38

Removing

lange

2

Withdraw
front
seal

assembly

INSPECTION

I
Check

poppet
assembly
for
condi

tion
If
it

shows
evidence
of

wear
or

damage

replace
it

and
valve

operating

rod

assembly

2
Check
other

component
parts
for

condition
If

any

part
shows
evidence

of
wear
or

damage
replace
it
with

a

new
one
Brake

System

ASSEMBLY
AND

ADJUSTMENT

Assemble
in
the

reverse

sequence
of

disassembly

Rear
shell

seal

1

Apply
a

coating
of

Master
Vac

grease
to

the

sealing
surface
and

lip
of

seal
and

install
that
seal
in

rear
shell

with
the

use
of

Master
Vac
Oil
Seal

Retainer
Drift

ST08060000

Fig
BR
39

Installing
oil
seal

Note

Referring
to

Figure
BR
40
in

stall
seal
in

place

by
properly

aligning
the

pawl
of

special
tool

with

seal
hole

Adjustment
is
cor

rect
when

specified
length
at

A
is

obtained

Length
A

6
7
to
7
Omm

0
264
to
0

276
in

BA1S5

Fig
BR
40

Length
at
A

Diaphragm
plate

I

Apply
a
thin

coating
of

grease
to

the

sliding
contact

portion
on
the

periphery
of

plunger
assembly

BR
17
1

SR1S6

Fig
BR

41

Requiring

grease
place

2

Install

plunger
assembly
and

silencer
in

diaphragm
plate
and

lightly

push

plunger

stop
key
in

place

Note

Diaphragm

plate
is
made
of

bakelite
Exercise

care
in

instaJJing

plunger
assembly
not
to

damage

diaphragm
plate

BROB3

Fig
BR
42

Inserting
stop
key

3
Before

installing

diaphragm
into

position
apply
a
thin

coating
of
mica

power
to
it

except
outer
diameter

and

seating
portion
with
which
shell
comes

into

contact

4
Before

installing
reaction
disc
in

place
on

diaphragm
plate
apply
a
thin

coating
of
Master
Vac

grease

Front
shell

seal

Before

installing
front

shell
seal
as

sembly

apply
a

coating
of
Master
Vac

grease
to
the
inner
wall
of
seal
and

front

sheU
with
which
seal

comes
into

contact

Final

sssembly

Apply
thin

coating
of
Master
Vac

grease
to
the
outer

edges
of

diaphragm

with
which

rear
and
front
shells

come

into
contact
before

instaIling
dia

phragm
in

position

2
Before

installing
push
rod
assem

bly
in

place

apply
a

coating
of

Master
Vac

grease
to
the

sliding
con

tact
surface
of

diaphragm
plate

3

Align
marks
scribed
in
the

rear

shell

and
front
shell

Carefully
turn
the

Master
Vac
Wrench
ST08080000

clockwise
until
it
reaches
notch
in

shell

retainer

Fig
BR
43

Tightenilll
reor
shell

4

After

assembly

adjust
the

length

of

push
rod
to
less
than
the

specified

value
indicated
below

Length
adjust

ment
of

push
rod
is

made
at
the

tip
of

push
rod

HAND
BRAKE
Stick
lever

typ
e

REMOVAL

HAND
BRAKE

Stick

lever

type

The
hand
brake

system
is
of
a
cable

reaction

type
which
actuates
rear
Brake

System

Length
B

10
0

to
10
5
mID

0
394

to
0
413
in

rl

J

BA290

Fig
BR
44

Lelll
th
at

B

Fig
BR
45

Adjusting
push
rod

length

HAND
BRAKE

CONTENTS

BR
18

BR
19
INSPECTION

INSTALLATION

wheel
brake

shoes
All

the
cable
ad

justment
can
be
made

by
operating

BR
18
INSTALLATION

Install
in
the

reverse

sequence
of

removal

Tightening
torque

Master

cylinder
to

Master
Vac

0
8

to
I

1

kg
m

6
to
8
ft
lb

Master

Vac
to

body

0
8

to
1
1

kg
m

6
to

8
ft
Ib

Note

After
Master
Vac
is

properly

installed
on
vehicle
be
sure
to

conduct
an
air

tight
test
and

oper

ation
test

described

previously
in

this
section

BR
19

BR
19

only

adjusting
nut
at
balance
lever

1
Control
bracket

2
Control
lever

3
Control
stem

4
Front

cable

5

Balance
lever

6
Rear
cable
R
H

7

Rear
cable
L
H

REMOVAL

Control
stem

I

Disconnect

terminal
from
hand

brake

warning
switch

2

Remove
nuts

securing
control

bracket
in

place
on
dash

panel
Brake

System

BAS6l

Fig
BR

46
Hand
brake

linkage

3

Pull
out
lock

pin
and
colter

pin

and

then

remove
control
stem

assem

bly

y
J

b
i1

I

I
1

II

i

l

I
BR773

Front

cable

Fully
release

control
stem

2

Loosen

adjusting
nut
at
balance

lever

3

Disconnect
front
cable
from
con

trollever

4

Remove
retainer

spring
at

cable

guide
bushing
Fig
BR

47
Control

stem

5

Disconnect
rear
cables
R
H
and

L
H
from
balance
lever
brackets

See

Figure
BR
48

6
Remove
balance
lever
brackets

from
crossmember

7

Detach
front
cable

clip
and

pull

front
cable

rearward

BR
19
k

1

BR663

Fig
BR
48
Balance
lever

Rear
cable

Fully
release
control

stem

2

Remove
both
rear

brake
drums

and
disconnect
rear
cable
from

toggle

lever

3

Detach

spring
and

spring
retainer

4

Remove

rear
cable
from
brake

disc

5

Disconnect
rear

cable
from

balance
lever
bracket

6

Detach
cable

clips
and

remove

rear
cable

INSPECTION

1

Check
control
stem
and
ratchet

for

evidence
of
wear
or

other

damages

Replace
parts
which
are

faulty

2

Replace
worn
or

fatigued
springs

3

Check
wires

for
evidence
of
dis

continuity
or
other
deterioration
Re

place
if

necessary

4

Replace
faulty
warning
light

and
or
switch

S

Check

parts
at
each
connection

and
if
found
deformed

or

damaged

replace

INSTALLATION

Install

hand
brake

assembly
in
the

reverse

sequence
of
removal

by
closely

observing
the

following
instructions

When

installing
apply
a

coating

of

grease
to

sliding
contact
surfaces

Make
Sure
that

each
sliding

part
func

lions

smoothly

2

Upon
completion
of
installation

of
hand
brake

assembly

adjust
the

entire

system
referring
to
the
instruc

lions
described
under

topic

Adjust

ment

3

Make
sure
that
each
cable
is

not

interfered
with

by

any

adjacent
parts

Do
not

apply
an
undue
stress
to

cables

Brake

System

SERVICE
DATA
AND
SPECIFICATIONS

Brake

pedal

Free

height

Free

play
at

pedal
pad

Full
stroke

at
pedal
pad

Depressed
height
mOl
in

mOl
in

mOl
in

mm
in
148
S

83

I
to
3
0

04
to
0

12

134
to
140
5
28
to
S
51

43
to
49

169
to
193

Brake

adjustment
notches

Front

Rear
12

12

Master

cylinder

Inner
diameter

Piston
to

cylinder
deaJance
mm
in

mm
in
19
0S

Yo

O
IS

0
OOS9

Master
Vac

Diaphragm
diameter
mOl
in

Maximum
vacuum
leakage
after
15
sec

mmHg
inHg

Shell
seal

depth
A
mOl
in

Push

rod

length
B
mOl
in
152
4
6

2S
0
98

6

7
to
7
0

0
264
to
0
276

10

0
to
10
5
0
394
to
0
413

Front
drum
brake

Type

Wheel

cylinder
inner
diameter

Lining

Width
x
Thickness
x

Length

Lining
wear
limit
Uni
servo

mm
in
I9
0S

Yo

45
x

4
5
x

244

1
77
x
0
177
x
9
61

1

0
0
039
mm
in

mOl
in

Rear
drum
brake

Type

Wheel

cylinder
inner

diameter
Duo
servo

mOl
in
19
0S

Yo

Brake

drum

Inner
diameter

Repair
limit
of

thickness

Inside
runout
mm
in

mOl
in

mOl
in
254
0
10

2SS
S
10
06

0
02
0
0008
maximum

PaJking
brake

Type

Stroke

Adjuster
sliding
resistance
mm
in

kg
lb
Stick

type

80
to
100
3
lS
to
3
94

S

to
12
11

to
26

BR
20

Brake

System

Tightening

torque

Master

cylinder
to
Master
Vac

kg
m
ft
Ib

0
8
to
l
l
6

to
8

Brake
tube

flare
nut

kg
m

ft
Ib
I
S

to
1
8

II
to
13

Brake

hose
connector

kg
m

ft
lb
1
8
to
2
1
13
to
IS

Air

bleeder
valve

kg
m
ft
lb

0
7
to
0

9
S
to
7

Fulcrum

pin
of
brake

pedal
kg
m

ft
Ib
1
2
to

1
5
9
to
II

Connector
and

clip

fIXing
bolt

kg
m
ft
lb

0
35
to
O
4S

2
5
to
3
3

3

way
connector

fIXing
bolt

kg
m
ft

Ib

0
8
to
l
l

6
to
8

on
rear
axle

case

Brake

pedal
stopper
lock
nut

kg
m
ft
Ib
1
2

to
1
5

9
to
II

N
L
S
V

to

body

kg
m
ft
Ib
0
8
to
l
l

6
to
8

Wheel

cylinder

mounting
nut

Front

kg
m
ft

Ib
S
4

to
6
6
39

to
48

Rear

kg
m
ft
Ib

1
5
to
1

8
II

to
13

Wheel

cylinder
connector
bolt

kg
m
ft
lb
1
9

to
2
5

14
to
18

Brake
disc
Back

plate
nut

Front

kg
m
ft

Ib
4
2
to
S

O
30
to
36

Rear

kg
m
ft

Ib
S
4

to
6
4
39
to
46

Master
Vac

Master

Vac
to

body
nut

kg
m
ft
lb
0

8
to
l
l
6
to
8

Flange
to

shell
cover
nut

kg
m
ft
lb

0
8
to
1
1
6
to

8

Operating
rod
lock
nut

kg
m

ft
Ib
1
6
to
2
2
12
to

16

Push
rod

adjusting
nut

kg
m

ft
Ib
1

9
to
2
4
14
to
17

BR
21