1977 DATSUN PICK-UP ABS

REFRIGERATION

SYSTEM

If

you
were
to

paint
your
finger

with
alcohol

your
finger
would
feel

cold
This
is
because
the

liquid
alcohol

takes
heat

away
from

your
finger

while
it

evaporates
If
a

quickly
evapo

rating

liquid
such
as
alcoliol
is

placed

in
a
container
inside
a
box
the
tem

f

Outside
air

U

Condenser

J6G1
i
i

1
1

t1

1

ilill
I
I

J

JJ
LlJ
i
l

7

U

Receiver

dryer

h

w

t

CONDENSER

The
condenser
is
installed
to
the

front
of
the
radiator

The
heated
and

compressed

refrigerant
gas
from
the
Air

Conditioning

perature
inside
the
box
will

drop
This

is
because
the

alcohol
is

evaporated

absorbing
the
heat
from
the
air

insidc

the
box
If
the

gaseous
alcohol
is

collected
and

cooled
with

cold
water

it
will
be

changed
back

into
a

liquid
by

absorption
of
its
heat

by
the
cold

water

The
cooler

operates
on
this

princi

Compressor

t

q
ttLJ

IrJ

Evaporator
It

J

1

J

f
9

d

lUr

I

Expansion
valve
V7777
J
High
pressure

lLLLLL
l

gas

I
I
High
pressure

liquid

t

u

compressor
condenses
to
a

liquid
by

being
cooled

by
air

passing
between

the
fins
of
the
condenser

1
GJ
7

vlmnn

iii

plI

d1i
1il

Ac459

Fig
AC

3
Condenser

AC3
pIe
The

liquid
used

is
the

refrigerant

R
12

The
heat
inside
the

passenger

compartment
is
absorbed

by

changing

the

refrigerant
from
a

liquid
to
a

gas

and
then

dissipated
to
the

outside

by

changing
the

refrigerant
from

a

gas

back
to
a

liquid

The

refrigeration
system
is

shown

in

Figure
AC
2

Low

pressurt

liquid

1

I
L2
Low

pressure

gas

Inside
air

li

r

L

Blower
motor

AC458

Fig
AC
2

Refrigeration
cycle

COMPRESSOR

The

compressor
is
installed
to
the

side

of
the

engine
and
is
driven

by

crank

pulley
through
a
belt
The

refrig

erant

gas
leaving
the

evaporator
is

forced
out
to
the
condenser

by
com

pressor
and
the
low

pressure
refrig

erant

gas
is

compressed
to
a

high

pressure
and

high

temperature

The

driving
force
is
transmitted

by

an
electrical
clutch
Because

engine

rpm
is

very
low

during
idling
the

clutch
will

not
transmit

the

driving

force
thus

ensuring
smooth

engine

idling

REFRIGERAi
H
R
12

COMPRESSOR
OIL

MAINTENANCE

PERIODIC
MAINTENANCE
AND

SEASON
IN

INSPECTION

GENERAL
SERVICE
INSTRUCTION

SAFETY

PRECAUTIONS

EV

ACUA
TlNG
AND

CHARGING
SYSTEM

HANDLING

MANIFOLD
GAUGE

HANDLING
SERVICE
VALVE

HANDLING
CAN
TAP

DISCHARGING
SYSTEM

REFRIGERANT
R
12

The

refrigerant
used
in
the
air

conditioner
is

generally
called
Re

frigerant
12

R
12
No
other

refrig

erant
than
the

above

refrigerant
should

be
used

This

refrigerant
is

usually
available

in
a
small
can
or
a

cylinder
In

either

case
it

is

liquefied
under

high
pressure

in
the
container

Refrigerant

evaporates
easily
has
a

low

evaporation
point
and
moreover

since
the
latent

heat
of
the

refrigerant

is

large
it

can
abSorb

a

large
amount

of
heat

wh

err
e

vaporating
Extreme

care
must
be
exercised
when

handling

the

refrigerant

COMPRESSOR
OIL

The
SUNISO
5GS
or
SUNISO

351

should
be
used
as

refrigeration

lubricant

Mixing
of
the

two
is

allowable

The

refrigeration
lubricant
should

be
used
to
assure
the
successful
com

pressor
operation
Use
of
oils
other

than
recommended
or

mixing
of
the

oil

with
other
oils
would
cause

chemical
reaction

or
lead
to
lowered

viscosity
or
deficient
lubrication

The
oil

absorbs
moisture
as
it

con

tacts

the
air
This

points
out
the
need

for

care
not
to

expose
it

to
atmos

phere
for
an

extended

period
of
time
Air

Conditioning

GENERAL
SERVICE

CONTENTS

EVACUATING
SYSTEM

CHARGING
REFRIGERANT

CHECKING
FOR
LEAKS

HALIDE
LEAK

DETECTOR

ELECTRIC
LEAK

DETECTOR

REFRIGERANT
LEVEL
CHECK

SIGHT

GLASS

PERFORMANCE
TEST

COMPRESSOR
OIL
LEVEL
CHECK

PERFORMANCE
TEST

REFRIGERANT

LEAKS
AC
8

AC

8

AC
8

AC
8

AC
8

AC
9

AC
9

AC
9

AC10

AC

11

AC
12

MAINTENANCE

PERIODIC
MAINTENANCE

AND

SEASON
IN

INSPECTION

Both

periodic
maintenance
and

season
in

inspection
are

most
essential

to
enable
the
air

conditioner
to

give

full

performance

Perform
the

following
checks

Start

engine
and

check

refrigerant

level

through
sight
glass
on

receiver

dryer
For

details
refer
to

relative

topics
under

Refrigerant
Level

Check

2
Check
the
entire

sysiein
for

sign

of

refrigerant
leaks

Refer
to
relative

topics
under

Checking
for

Leaks

and

Refrigerant
Leaks

If

any
trace
of
oil
is

noted
at

and

around
connection

fittings
it
is
a

sure

indication

that

refrigerant
is

leaking

This
condition

can
be
corrected

easily

by
retightening
the

joints
If

any
joint

on
line

is

suspected
of
small
amount
of

leakage
use
a
leak

detector
to

locate

leaking
points

3
Check

compressor
drive
belts

for

proper
deflection

Season
off

Observe
the

following
maintenance

tips
to
allow

the
air

conditioner

to

operate

normally
in

the
next

season

I

Keep
the
entire

system
free
from

AC
8
AC12

AC

13

AC15

AC15

AC16

AC

16

AC16

AC
17

AC17

AC
17

AC18

refrigerant
leakage
by

periodically

checking
for

refrigerant
gas
leak

even

out
of
season

2

Turn
the

compressor
for
10

minutes

at
least
once
a
month

by

running
the

engine
at
1

500

rpm

c
ENERAL
SERVICE

INSTRUCTION

The

servicing
of
the
air
conditioner

should
be
carried
out

only
by
well

trained
servicemen
This

chapter
de

scribes
essential

points
of

servicing

Jf

a

Jarge
amount
of

dirt
and
sand

enter

the

system
they
will
be

carried
with

refrigerant
and

may

clog
the

system
or
scratch

rotating

parts
This

points
out
the
need
for

care
in

servicing
the

system
That

is

disconnecting

joints
should
be

carried
out

in
a
dean

place

Water
should
not
be
allowed
to

get

inside
the

system
The

refrigerant

does
not

readily
mix

with
water

However
the

presence
of
even
a

minute

amount
of

water
will
cause

a
chemical
reaction

at

high
tem

perature
which
will
in

turn

produce

hydrochloric
acid

HCl
Since

hydrochloric
acid
is

highly
corro

sive
to
metals
the
aluminum
and

copper
piping
etc
will
become

corroded
and
the

refrigeration

system
will
become

clogged

Water
in
the

system
will

ice
the

orifice
when
the

high
pressure
re

frigerant
is

changed
to
low

pressure

refrigerant
by

expansion
valve
etc

and
will
obstruct
the

refrigerant

flow

The

following
items

are

general

instructions
to
be

closely
observed
in

servicing
the

system

I
When
a

system
line
is

discon

nected

plug
the

opening
immediately

This
is

especially
necessary
to

prevent

moisture

condensation
from

forming

in
the
line
and
to

keep
out
dirt
and

dust
It
is
also

necessary
to

keep
the

line
at
and
above

surrounding
air

temperatures
at
all

times
When

con

necting
system
lines
do

not

attempt

to
remove
the

plug
from
the

opening

until

ready
for
immediate
use

2

Always
keep
the

working
place

clean
and

dry
and
free
from
dirt
and

dust

Wipe
water
off
with
a
clean

cloth

3
Have
all

necessary
tools
in

pre

paration
beforehand

and
have

tools

clean
and

dry

4
The

compressor
oil
will

easily

absorb
moisture
when

exposed
to
air

Immediateiy
close
the

opening
of
the

container
after
use
It
is
also

necessary

to
observe
the

following
notes

Notes

a
The
oil
should
not
be
transfused

from
a
container
into

another
as

the
failure

will

possibly
cause
mois

ture
to
mix

with
the
oil

b
The

used
oil
should
not
be

returned

into
a
container

c

The
oil

should
not

be
used
if
its

state
of

preservation
is

not
clear

enough

5
When

connecting
or

disconnect

ing
pipes
from
the

refrigeration
sys

tem
use
two

wrenches
One
wrench
is

used
for

holding
the

fixing
nut

in

place

while
the

other
for

turning
the

mating

flare

nut
Failure
to
do

so

may
result

in
a

twisted
tube
or

may
damage

connection

6
Also
use
care
not
to

give
scratches

to
the

seating
surface
at
connections

A

small
scratch
on

the

seating
surface
Air

Conditioning

may
be
the
cause
of

gas
leakage

Before

connecting
pipes
be
sure
to

give
coating
of

compressor
oil
to
the

sea

ting
surfaces

SAFETY

PRECAUTIONS

I

Since
direct

contact
of
the

liquid

refrigerant
with

your
skin
will
cause

frostbite

always
be
careful

when

handling
the

refrigerant
Wear

gloves

or

wrap
a

piece
of
cloth
around
service

valve

to

protect
your
fingers
against

frostbite

by

refrigerant
If

any
of
the

refrigerant
should

get
into

your
eyes

when

charging
the

refrigerant
splash

your
eyes
with

cool
water
to
raise

the

temperature
gradually
Apply
a

protec

tive

film
to

the

eye
to

avoid
infection

Do
not
rub

your
eyes
Consult
an

eye

specialist
Always
wear

goggles
or

glasses
to

protect
your
eyes
when

working
around
the

system
Should

refrigerant
strikes

your
body
splash

on
cool
water
and

apply
a

protective

film

2
The

refrigerant
service
container

has
a

safe

strength
However
if
han

dled

incorrectiy
it
wili

explode

Therefore

always
follow
the
instruc

tions
on
the

label
In

particular
never

stpre
it
in

a
hot

location
above

S20C

l250F
or

drop
it
from

a

high

height

3
The

refrigerant
gas
is

odorless
and

colorless
and

breathing
may
become

difficult

due
to
the

lack
of

oxygen

Since
the

refrigerant
gas
is

heavier
than

air
and

will

lay
close
to
the
floor
be

especially
careful
when

handling
it

in

small

confined

spaces

4

The

refrigerant
itself
is
nonflam

mable
However
a

toxic

gas

phosgene

gas
is

produced
when
it

contacts
fire

and

special
care
is
therefore

required

when

checking
for

leaks
in

the

system

with

a
halide
torch

5

Do
not
steam

clean
on
the

sys

tern

especially
condenser
since
exces

sively
high
pressure
will
build

up
in

the

system
resulting
in

explosion
of
the

system

The

above

precautions
are
essential

in

handling
of

Refrigerant
l
2
and

their
strict
observation

requires
suffi

AC
9
dent

training
Therefore
it
is

of
first

importance
that

any
other

personnel

than
a
well
trained
serviceman
should

not
be

allowed
to
handle
the

refrig

erant

EVACUATING

AND

CHARGING
SYSTEM

During

servicing
use
caution
to

keep
air

from

getting
into

refrigerant

When
air

enters
the

system
all

refriger

ant

must
be
evacuated
from

system

prior
to

charging
new
refrigerant
Air

in

refrigerant
has
the

following
delete

rious

effects

I

Since
the
condensation

tempera

ture

of
the
air
is

extremely
low
the
air

will

not
be

condensed
when

refrigerant

gas
is
condensed

in
the
condenser
and

the

air
will

thus
remain
in

gaseous

form

Consequently
the
effective

thermal

transmission
area

of
condenser

for

refrigerant
gas
will
be
red
uced
and

refrigerant
gas
to
be
condensed
will
be

red
ueed
The

pressure
rise
will
become

proportional
to

the
volume
of
the
air

in

system

2

When
air
and

refrigerant
are

mixed
in

system
a
chemical
reaction

will
be

produced
and

hydrochloric

acid
which
will

adversely
affect
the

aluminum

copper
iron
and
other

materials
in

system
may
be

generated

HANDLING
MANIFOLD

GAUGE

The

pressure
at
the

high
and
low

sides
of

system
should
be

measured

when

evacuating
and

charging
refrig

erant
and
when

diagnosing
trouble
in

the

system
The
manifold

gauge
is
used

for
these

purposes
A

manifold

gauge

has
two

pressure
gauges
a

low

pressure

gauge
and
a

high
pressure
gauge
These

gauges
are

connected
to

the

high
and

low

side
service

valves
of

system

through
flexible

charging
hoses

The

construction

of
manifold

gauge
is

shown
in

Figure
AC
13

When
valve
stem
is

fully
screwed

the
valve
is
front
seated
and
valve

path

and
the
center

path
are
blocked
When

valve
stem
is

backed
off
the

paths
are

opened