1977 DATSUN PICK-UP stop start

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

Body
Electrical

System

RADIO

Noise

prevention

Position
vehicle
in
an

open
area

away
from
steel

buildings
run

engine
extend
antenna
to
its
maximum

length
set
volume

control

to
maximum
and
set
dial
at
a
medium

point
without

catching
broadcasting
wave

Condition

Ignition

system

Noise
occurs
when

engine
is

op

erated

Charging
system

Sound
of

alternating
current

pre

sents

When

accelerator

pedal
is

depressed

or

released
noise

presents

Supplement
equipment

When

engine
starts
noise

presents

Noise

still

presents
even
after

stop

ping
engine

Notes

a
Be
sure
to
locate

capacitor
as

close

as
to

noise
source
and
connect
in

parallel
Probable
cause
Corrective
action

High
tension
wire

Install
new

high
tension
wire

Ignition
coil
Install
a
0

51lF

capacitor
to

primary
side

terminal
of

ignition
coil

Note
Be

careful
not
to
install

capacitor
to

secondary
or

primary
breaker
side
other

wise

engine
becomes

improper

Install
bond

strap

Distributor
Secure
contact
of
carbon
electric

pole
and

rotor

Eliminate

sharp
tip
on

rotor

pole
or

cap
pole

by

scrubbing
with
a

screwdriver

Check

stagger
between
rotor

and
stator

Alternator
Install
a
0

51lF
capacitor
to

charging
termi

nalA

Note
Do

not

use
a
larger
capacitor

If

capacitor
is

installed
to
terminal
F

alternator
coil
will
be

damaged

Regulator
Install
a
0

51lF
capacitor
to
IGN
terminal

of

voltage
regulator

Operative
noise
of
water
tem

perature
and
fuel

gauges
Install
O

IIlF
capacitor
between
terminal
and

ground
wire

Note
If

a

capacitor
having
a

larger
capacity

is
used
indication
of

gauge
will
be
de

viated

b
Cut
lead
wire

as
short
as

possible

c

Ground
wire
should
be
attached
on

the

body

completely

d
Make
installation
and
connection
securely

e

Carefully
identify

or
OUT

mark
IN

BE
35

DISCHARGING
SYSTEM

The

pressurized
refrigerant
gas
Ul

side

system
must
be

discharged
to
a

pressure
approaching
atmospheric

pressure
prior
to

evacuating
refrigerant

inside

system
This

operation
should

be
made
to

permit
safe
re
oval
when

replacing
system
components

I

Close

high
and
low

pressure

valves
of
manifold

gauge
fully

2

Connect
two

charging
hoses
of

manifold

gauge
to

their

respective

service
valves

3

Open
both
manifold

gauge
valves

slightly
and

slowly
discharge
refriger

ant
from

system
See

Figure
AC
17

Note

Do
not
allow

refrigerant
to
rush

out
Otherwise

compressor
oil
will

be

discharged
along
with
re

frigerant

AC735

Fig
AC

17
Discharging

system

Caution
Protect

fingers
with
cloth

against
frostbite

by
refrigerant

when

connecting
the

charging
hose

to

the
service
valve

or

disconnecting

it
therefrom
Air

Conditioning

EVACUATING
SYSTEM

1
Connect

high
and
low

pressure

charging
hoses
of

manifold

gauge
to

their

respective
service

valves
of

sys

tern

and
d

ischarge

refrigerant
from

system
Refer
to

Discharge
System

2

When

refrigerant
has
been

dis

charged
to

a

pressure
approaching
at

mospheric
pressure
connect
center

charging
hose
to
a

vacuum

pump

3
Close
both
valves
of
manifold

gauge
fully
Then
start

vacuum

pump

4

Open
low

pressure
valve
and
suck

old

refrigerant
from

ystem
See

Figure
AC
18

S

When
low

pressure
gauge
reading

has

reached
to

approximately
500

mm

Hg
20
in

Hg
slowly
open
high

pressure
valve

See

Figure
AC
19

6
When

pressure
inside

system
has

dropped
to

710
mm

Hg
28
in

Hg

fully
close
both
of

valves
of
manifold

gauge
and

stop
vacuum

pump
Let

stand
it

for
5

to
10
minutes
in

this

state

and
confirm
that
the

reading

does
not
rise

Notes

a
The
low

pressure
gauge
reads
lower

by
2S

mm

Hg
I

in

Hg

per
a
300

m

1
000
ft
elevation
Perform

evacu

ation

according
to
the

following

table

Elevation

m
ft
Vacuum
of

system

mm

Hg
in

Hg

0

0

300

I
000

600
2
000

900
3

000
710
28

68S
27

660
26

635
25

Note
Values
show

readings
of
the

low

pressure
gauge

AC

12
b
The
rate
of
ascension
of
the
low

pressure
gauge
should
be
less
than

2S
mm
Hg
I

in

Hg
in
five

min

utes

If
the

pressure
rises
or
the

specified

negative

pressure
can
not
be
obtained

there
is
a

leak
in
the

system
In
this

case
immediately
charge

system
with

refrigerant
and

repair
the
leak
de

scribed
in
the

following

I
Confirm
that
both
valves
of

manifold

gauge
are

fully
closed
and

then
disconnect
center

charging
hose

from

vacuum

pump

2
Connect
center
hose
to
can

tap

in

place
of
vacuum

pump
Attach

refrigerant
can
to

can

tap
and

pass

refrigerant
to
manifold

gauge

3

Loosen
the
connection
of
center

fitting
of
manifold

gauge
to

purge
air

from

center
hose

4

Open
low

pressure
valve
of
mani

fold

gauge
and

charge
refrigerant
into

system
After
one
can
about
0
4

kg
I

Ib
of

refrigerant
has
been

charged

into

system
close
low

pressure
valve

5

Check
for

refrigerant
leakage

with
a
leak
detector

Repair
any
leak

ages
found
Refer
to

Checking
for

Leaks
and

Refrigerant
Leaks

6
Confirm
that
both
valves
of

manifold

gauge
are

fully
closed
and

then

change
center

charging
hose
from

can

tap
to
vacuum

pump

7

Open
high
and
low

pressure

valves
and

operate
vacuum

pump
to

suck

refrigerant
from

system
When

the

pressure
in

system
has

dropped
to

710

mm

Hg
28
in

Hg
fully
close

both
valves
of
manifold

gauge

7

The
above

operation
completes

evacuation
of

system
Next

charge

refrigerant
Refer
to

Charging
Refrig

erant

3

Piping

Flared
section
of

high
pressure
and

low

pressure
flexible

hose

Pipe
connections

rvice

valve

4

Evaporator
housing

Jnlet
and

outlet

pipe
connections

Expansionvalve

ELECTRIC
LEAK
DETECTOR

for
the

operational
procedures

refer
to

the
instructions
furnished
with

each
electric
leak
detector

Amount

of

refrigerant
Air

Conditioning

REFRIGERANT

LEVEL
CHECK

SIGHT
GLASS

Sight
glass
is

provided
at
the

top
of

receiver

dryer
One

guide
for
whether

there
is

enough
refrigerant
in

system
is

given
by
observing

refrigerant
flow

through
sight
glass
However
this

method

is
unsuitable
for

judging
the

amount
of

refrigerant
The
correct

refrigerant
level

can
be

judged
by

measuring
t
e

system
pressures
in
ac

cordance
with
the

procedures
de

scribed
Performance
Test

I

Start
the

engine
and
hold

engine

speed
at
1
500

rpm

Almost
no

reftigerant

Check
item

Temperature
of

high
pressure

and
low

pressure
pipes
Almost
no
difference

between

high

pressure

and
low

pressure
side

temperature

Bubbles
flow
continu

ousty
Bubbles
will

disappeu
a
nd
some

thing
like
mist

will

now
when

rerrigeran

is

nearly
gone
State
insightglass

A

I
I

AC256

Pressure
of

system
High
pressure
side

is

abnormally
loW

Repa
ir
Stop

compressor
and

conduct
an
overall

check
Insufficient

High
pressure
side
is

warOl
and

low

pressure

side

is

fairly
cold

The
bubbles
are
seen

at
intervals
of
1
2

seconds

A

r

I

AC257

Both

pressures
on

high

and
low

preS
ure
sides

are

slightly
low

Check
for

gas
leakage

repair
as

required
re

plenish
and

charge

system

AC

16
2

Set

temperature
control
lever
to

maximum

position

3

Set
blower
to
maximum

speed

4

Check

sight
gla
after
the

lapse

of
about
five

minutes
Judge
according

to
the

following
table

AC741

Fig
AC
26

Temperature
control
lever

Suitable
Too
much

refri
crant

High
pressure
side
is

hot
and
low

pressure

side
is
cold
High

pressure
side
is

abnormally
hot

Almost

transparent

Bubbles

may
appear

when

engine

speed
is

raised
and
lowered
No
bubbles
can
be

seen

No
clear
difference
exists
between
these
two

conditions

M

II
I

AC258

Both

pressures
on

high

and
low

pressure
sides

are
normal
Both

pressures
on

high

and
low

pressure
sides

are

abnormally
high

Discharge
reft

gerant

from

service
valve
of

10
11

pressure
side

Notes

a
The
bubbles
seen

through
the

sight

glass
are
influenced

by
the
ambient

temperature
Since
the
bubbles
are

hard
to
show

up
in

comparatively

low

temperatures
below
200C
6S0

F
it
is

possible
that

a

slightly

larger
amount
of

refrigerant
would

be
filled
if

supplied
according
to

the

sight
glass
Be

sure
to
recheck

the
amount
when
it

exceeds
200C

680F
In

higher
temperature
the

bubbles
are

easy
to

show

up

b

When
the

screen
in
the

receiver

dryer
is

clogged
the
bubbles
will

appear
even
if
the
amount
of

refrig

erant
is
normal
In
this
case
the

outlet
side

pipe
of
the
receiver

dryer
becomes

considerably
cold

PERFORMANCE
TEST

Check
for
the
amount
of

refrigerant

in
the

system
can
be

made

by
meas

uring

pressure
on

discharge
side

The

correct
amount
of

refrigerant
is

in
the

system
if

pressure
on
the

discharge
side
is
within

the

specified

range
For
details
refer
to

Perform

ance

Test
described
later

Overcharging
will
show

up
in

higher

pressure
on
discharge
side

COMPRESSOR
OIL

LEVEL

CHECK

The
oil

used
to
lubricate

compres

sor
circulates
into

system
from
the

oil

sump
while

c9mpressor
is

operating

The

efore
to

correctly
measure
com

pressor
oil
the

amount
of
oil

flowing

to

system
must
be

considered
If
a

considerable
amount
of

leakage
of

refrigerant
gas
happens
the

leakage
of

compressor
oil
is
also
considered

There

will
be

no

compressor
oil
leak

age
from
a

completely
sealed

system

When

system
operates
under

satisfying

condition
the

compressor
oil
level

check
is

unnecessary

When

checking
the
level

of
com

pressor
oil
or

when

replacing
any

component
part
of
the

system
use
the

following
service

procedure
This

fa

cilitates
to
return
oil
to

compressor

I

Operate
compressor
at

engine

idling
speed
1
000

rpm
or

below

with
controls
set

for
maximum

cooling
Air

Conditionin
j

and

high
blower

speed
for
10
to

15

minutes
in

order
to
return

compressor

oil
to

compressor

2

Stop
the

engine
and

discharge

refrigerant
of

system
and
then

remove

compressor
from

the
vehicle

3
Remove

compressor
fIller

plug

Drain

compressor
oil
from

compres

sor
oil

sump
and

measure
the

amount

4

Compressor
oil
is

satisfactory
if

the

following
amount
of
oil

remains
in

the

compressor

Residual
oil

S5
to
128

gr
3
to
4
oz

5
Check
the
cleanliness
of
the
oil
If

the
oil
contains

chips
or

other

foreign

material
clean
oil

5ump
with
new

oil

6
Discard
the

used
oil
and

fili
with

the
same
amount
of
new
oil
Add

oil
if

found
less
than
above
amount

Fig
AC
27

Filler

plug

If

compressor
is

inoperative
due
to

faulty
compressor
or

heavy
loss
of

refrigerant
remove

compressor
and

repair
as

necessary
Then

pour
oil

up

to
correct
level
and
install
on

engine

After
above

steps
have
been

complet

ed
recheck
oil
level
drain
oil
to

correct
level
if

level
is

excessively
high

PERFORMANCE
TEST

The
cooling

performance
of
the
air

conditioner

changes
considerably
with

changes
in

surrounding
conditions

Testing
must
be

performed
using
the

correct
method
This

test
is
used
to

judge
whether

system
is

operating
cor

rectly
and

can
also
be
used

as
a

guide

in

checking
for

problems

I

Park
the
vehicle
indoors
or
in
the

shade

AC
17
2

Open
all
the
windows
of
the

vehicle
fully
However

close
the

doors

3

Open
the
hood

4

Connect
manifold

gauge
to

high

and
low
side
service
valves
of
the

system
Refer
to

Handling
Manifold

Ga

uge

5

Set
fan
control
lever
to
maxi

mum

6
Set

temperature
control
lever

to

max
cool

position

7
Start
the

engine
and
hold

engine

speed
at
1
500

rpm

S
After
the
air

conditioner
has
been

operated
for
about
10
minutes

measure

system

pressures
at

high
pres

sure

discharge
side
and
low

pressure

suction
side

9
Measure
the

temperature
of
dis

charge
air
at

outlet

grille

10
Measure
the

temperature
of

capin

11
Measure
ambient

temperature

and

humidity
one
meter
3
3
ft

away

from
condenser
front
Be

careful
not

to

expose
dry
buib

and
wet
bulb

to

direct

sunlight

12
Check
for

any
abnormalities

by

comparing
the
test

results
with
stand

ard

pressure
in
Performance

Chart

Notes

a
The

pressure
will

change
in
the

followi

g
manner
with

changes
in

conditions

When

blower

speed
is

low
dis

charge

pressure
will

drop

When
the
relative

humidity
of
in

take
air
is
low

discharge
pressure

will

drop

b

The

temperature
will

change
in
the

following
manner
with

changes
in

conditions

When
the
ambient
air

temperature

is

low
the
outlet
air

temperature

will
become
low

If
the
test
reveals
that
there
is

any

abnormality
in

system
pressure
isolate

the

cause
and

repair
by
reference
to

the
Trouble

Diagnoses
and
Cor

rections