ESP DATSUN PICK-UP 1977 Workshop Manual

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

Air
Conditioning

b

When

charging
hquefied
refrigerant

into
the

system
lith
the
can
turned

upside
down
to
reduce

charging

time

charge
it

only
through
high

pressure
valve
but
not

through
low

pressure
3
h
e

After

completion
of

charging
the

compressor
should

always
be

turn

ed
Several
times

manually
See

Figure
AC
22

t

UL
Q

v1ifl
j

AC739

Fig
A
C
22

ClUJrging
refrigerant
First

step

4
If

refrigerant
charging

speed
slows

down

charge
it
while

Iunning
the

compressor
for
ease
of

charging
After

having
taken
the

steps
up
to

3
above

proceed
with

charging
in

the

following

order

I
Shut
off

high

pressure
valve
of

manifold

gauge
back
into

refrigerant
can
and
can

may
explode

2

Run
the

engine
at

idling
speeds

about
1
500

rpm

3
Set
the

temperature
control

lever
and
fan
switch

at
maximum

cool

and
maximum

speed
respectively

4

Charge
refrigerant
while
con

trolling
low

pressure
gauge
reading
at

2
8

kgfcm2
40

psi
or
less

by
turning

in
or

out
low

pressure
valve
of
mani

fold

gauge
See

Figure
AC
23
Caution
Never

charge
refrigerant

through
high

pressure
side
of

sys

tem
since
this
will
force

refrigerant

t

AC740

Fig
A
C
23

Charging

refrigerant
Second

step

AC
14
5
When

refrigerant
can
is

empty

fully
close

both
Ives
of
manifold

gauge
and

replace
refrigerant
can
with

a

new
one

Before

opening
manifold

gauge

valve
to

charge
refrigerant
from
new

can

be
sure
to

purge
air
from
inside

charging
hose

6

Charge
the

specified
amount

of

refrigerant
into

system
by
weighing

charged
refrigerant
with
scale

Over

charging
will

cause

discharge

pressure

to

rise

AC255

Measure
the

amount
of

charged

refrigerant
with
a
scale

Make
a

note
of
the

amount

charged

from

can

Fig
AC

24
Measuring
refrigerant

Refrigerant
capacity

Unit

kg
lb

Refrigerant
Minimum

Maximum

R
12

0

7
1
5
0
9
2

0

Note
The

presence
of
bubbles
in

sight
glass
of

receiver

dryer
is
an

unsuitable
method
of

checking
the

amount

of

refrigerant
charged
in

system
The
state
of
the
bubbles
in

sight
glass
should

only
be
used
for

checking
whether
the
amount
of

charged
refrigerant
is
small
or
not

The
amount
of

charged
refrigerant

can
be

correctly

judged
by
means

of

discharge
pressure
Refer
to
Re

frigerant
Level
Check

7
After
the

specified
amount
of

refrigerant
has

been

charged
into

sys

tem
close
manifold

gauge
valves
Then

detach

charging
hoses
from
service

valves
of

system
Be
sure
to
install

valve

cap
to

service
valve

8

Confirm
that
there
are

no
leaks
in

system
by

checking
with
a
leak
detec

tor

Refer
to

Checking
for
Leaks

Note

Conducting
a
performance
test

prior
to

removing
manifold

gauge
is

a

good
sen
ice

operation
Refer
to

Performance

Test

CHECKING
FOR

LEAKS

Conduct
a

leak
test
whenever
leak

age
of
refrigerant
is

suspected
and

when

conducting
service

operations

which
are

accompanied
by
disassembly

Dr

loosening
of

connection
fittings
Air

Conditioning

Refrigerant
is
a

colorless
odorless

gas
and

leakage
from

system
is
diffi

cult
to
detect

Accordingly
the
use

of

a

leak
detector
facilitates

check
for

leaks

Two
methods
of

checking
are

available
one

employs
a
halide

leak

detector
which
burns

propane
gas
or

butane

gas
and
the
other

is
an
electric

type
leak

detector

HALIDE
LEAK
DETECTOR

Since
the

propane
leak
detector
and

butane
leak
detector

are
the

same
in

respect
to
their

operation
this

section

describes
the

operation
of
the

propane

leak
detector

The

copper
screen
is
heated

by
the

burning
of

propane
Refrigerant
gas

decomposes
to

color
the
flame
when

it

contacts
the
heated
screen
The

gas
to

be
checked
is
drawn
into

the

sampling

tube

and
sent
out
to
the
burner
A

refrigerant
leak
can

clearly
be
detected

by
variations
in
the
color
of
the
flame

Propane
type

NO
LEAK

SMALL

LEAK

LARGE
LEAK
Greenish

blue

Yellow

Purple
AC010
1

Copper
reaction

plate

2

Flame

adjusting
lines

3

Burner

4

Sampling
tube

5

Strainer

6

Gas
bomb

7
Flame

adjuster

Fig
A
C
25

Checking
for
leak

Butane

type

Pale
blue

Bright
blue

Vivid

green

AC
15
I

Discharge

refrigerant
in

one
or

two
seconds
to
ascertain

that

system

has
a

sufficient

pressure
needed
for

leak
detection

Charge
with
04

kg
I

lb
of

refrigerant
if

necessary

2

Light
leak
detector

Adjust
the

height
of

the
ilame
between

flame

adjusting
lines
at
the

top
and
bottom

of
combustion

tube
A

reaction

plate

will

immediately
become
red

hot

3

Place
the
end

of

sampling
tube

near
the

point
of
the

suspected
leak

in

system

Notes

a
Since

refrigerant
gas
is
heavier
than

air

small
leaks
can
b

easily
detect

ed

by

placing
sampling
tube
direct

ly
below
the
check

point

b
Suitable
ventilation
is

required
If

refrigerant

gas
is

mixed
with
the

surrounding
air
leak
detector
will

always
indicate
a

response
and

detection
of
the
actual
leak
will
be

difficult

c

Never
bold
leak
detector
at
an

angle

Cautions

a
Never

inhale
the
fumes

produced

by
combustion
of

refrigerant
gas

since

they
are
toxic

b
Never
use
halide
torch
in
a

place

where
combustible
or

explosive

gas

is

present

4
The

ilame
will
be
almost

colorless

when
there
is

no

refrigerant
gas
being

burned
When
there
is

a
small

refriger

ant

gas
leak
the
ilame

will
be

green
or

yellowgreen
When

refrigerant

gas
leak

age
is

large
the
ilame
will
be
brilliant

blue
or

purple
Since
the
color
of
the

ilame
will
be

yellow
when
dust
is

being
burned
Or
there
is

aging
scale
on

copper
reaction

plate
always
keep
the

strainer
of

sampling
tube
and
reaction

plate
clean

5

Major
check

points

I
Compressor

Compressor
shaft
seal

rotate
the

compressor
by
hand

Oil
filler

plug

Flexible
hose
connections

Rear
cover
and
side
cover

gaskets

Service
valve

2
Condenser

Condenser

pipe
fitting

Condenser
inlet
and
outlet

pipe

connections

I