refrigerant type DATSUN PICK-UP 1977 Service Manual

Page 504 of 537


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

Page 526 of 537


INSPECTION

Check
for

gas
leakage
as
follows

I

Plug
high
and
low

pressure
joints

on

compressor
with
blind

caps

2

Connect

charging
hoses
in
lines

between
manifold

gauge
and

high
and

low

pressure
service
valves

Connect

refrigerant
can

to
middle

hose
of

manifold

gauge

3

Open
valve
of
can

tap
and

charge

refrigerant
Loosen
oil
filler

plug
at

side
of

compressor
to

purge
air
out
of

compressor

4
Turn
shaft
5

or
6

turns
Then

confirm
that

pressure
does

not

decrease
on

low

pressure
gauge
If

gauge
indicates
a

pressure
decrease

there
is
a
leak

Conduct
a
leak
test

Under
such
a

condition
remove
and

then

install

parts
again

CYLINDER
HEAD

AND
VALVES

Insufficient

refrigerant
compression

is

likely
to
be
caused

by

damaged
head

gasket
or

damaged
valves

Prior

to

servicing
the
head
and
valve

plate
both
service

valves
should
be

opened
to
free

any
gas

pressure
which

may
be
in

the

compressor

REMOVAL

I

Remove
the
bolts

from

flanged

type
service

valves

using
Torx
Driver

Bit

Note
The
direction
of

flanged
type

service
valves

should
be
noted
for

reinstallation

AC812

Fig
AC
66

Removing
service
valves

2
Remove
the

remaining
bolts
in

the
head
Air

Conditioning

AC813

Fig
A
C
6
7
Removing

cylinder
head

bolts

3
Remove

valve

plate
and
head

from

cylinder
by
prying
or

tapping

under
the
ears
which
extend
from

valve

plate

If
head
and
valve

plate
adhere
hold

head
and

tap
valve

plate
ears

away

from

head
with
a

soft
hammer

Note
Do

not
hit
or

tap
head
to

separate
head
and
valve

plate
be

3use

damage
to
head

may
result

Fig
AC
68
Removing
valve

plate

and
head

4
When

removing
the

gaskets
use
a

sharp
edged
knife

Notes

a
In

removing
head

gasket
be

very

careful
not
to

damage
machined

sealing
surface

b
Do

not
reuse

gaskets

AC815

Fig
A
C
69
Removing
gasket

AC37
INSTALLATION

Valves
and
valve

plates
are
furnish

ed

only
as
a

complete
assembly

I

Apply
a
thin

film
of
clean

refrig

eration

oil
on
area
of
crankcase
to
be

covered

by
cylinder
gasket

2
Place

cylinder
gasket
in

position

on

cylinder
so
dowel

pins
in
crankcase

go
through
dowel

pin
holes
in

cylinder

gasket

3

Apply
a
thin

film
of
clean

refrig

eration

oil
to

top
and
bottom
valve

plate
areas
to
be
covered

by
gaskets

AC816

Fig
A
C
70
Applying
clean

refrigeration
oil

4
Place
valve

plate
in

position
on

cylinder

gasket
so

discharge
valve
as

semblies
i

e
smaller
diameter
assem

blies
with
restrainer

over
valve
reed

are

facing
up
and

locating
dowel

pins

go
through
dowel

pin
holes
in
valve

plate

Fig
A
C
71
Placing
valve

plate