1977 DATSUN PICK-UP open hood

to

facilitate
smooth

operation
of
air

control
valve

If
the
above
test
reveals

any
prob

lem

in
the

operation
of
air

control

valve

carry
out
the

following
test

4
Remove
air

cleaner
cover
Set

temperature
sensing
element
of
ther

mistor
or

thermometer
to
a

position

where

temperature
around
sensor
can

be

measured
In

this
case
fIx

wiring
of

thermistor
or

thermometer
on
the

bottom

surface
of
air

cleaner
with

adhesive

tape
in

such
a
manner
that

the

set

position
of

temperature
sensing

DESCRIPTION

OPERATION

DESCRIPTION

The
idle

compensator
is

basically
a

thermostatic
valve

which
functions
to

introduce
the
air

directly
from
the
air

cleaner
to
the

intake
manifold
to

compensate
for
abnormal
enrichment

of
mixture
in

high
idle

temperature

The
bi
metal

attached
to
the
idle

compensator
detects

the

temperature

of
intake
air
and

opens
or
closes
the

valve
Two

idle

compensators
having

different

temperature
characteristics

are

installed
one

opens
at
an
intake
air

temperature
of

60
to
700C
140
to

l580F

and
the
other
at
70

to
900C

158
to
1940F

OPERATION

The
construction
of
the
idle

com

pensator
is

shown
in
the

following
Engine
Fuel

element
will
not
be
affected

by
air

flow

Then
install
air
cleaner
cover

Fig
EF
13

Checking
temperature

sensor

IDLE
COMPENSATOR

CONTENTS
5

Carry
out
test
as
described
in

steps
I
2
and
3
above
When
air

control
valve

begins
to

open
to
under

hood
air
inlet
side
several
minutes

after

engine
starting
read
the

indica

tion

of
thermistor
or

thermometer
If

reading
falls
within
the

working
tern

perature

range
of

temperature
sensor

the
sensor
is

normal
If

reading
ex

ceeds
the

range

replace
the

sensor

with
new
one

Note
Before

replacing
temperature

sensor
check

idle

compensator
as

described
in

Idle

compensator

EF
7

EF
7
REMOVAL
AND
INSTALLATION

INSPECTION
EF

B

EF

8

q

EF222
1

Orifice

2
Bi
metal

3
Rubber
valve

Fig
EF

14
Structure

of
idle

compensator

Bi

metal
Intake
air

temperature

No

1
Below
600C
1400F

60
to
70
C

140
to
l580F

Above
700C

158
OF

Below
700C

1580F

70
to
900C

158
to
1940F

Above
900C
1940F
No
2

EF
7
The
idle

compensator

operates
in

response
to
the

under
hood
air

temper

ature

as
shown
below

Idle

compensator
operation

Fully
closed

Close
to

open

Fully

open

Fully
closed

Close
to

open

Fully

open

Notes

a

The
idle

rpm
and
CO

vary
accord

ing
to
the
altitude
Therefore

they

should
be

properly
adjusted
when

the

position
of
the
H
L
lever
is

changed

EF729

ADJUSTMENT

AND
INSPECTION

CARBURETOR
IDLE
R
P
M

AND
MIXTURE
RATIO

Cautions

3
On

automatic
transmission

equi

ped
models
check
should
be

per

formed
in

the
0

position

Be
sure
to

engage

parking
brake
and

to
lock
both
front
and

rear
wheels

with
wheel
chocks

b

Keep
your
foot
down
on
the
brake

pedal
while

depressing
the
accelera

tor

pedal
Otherwise
vehicle

surges

forward

dangerously

Notes

a
00
not

attempt
to
screw
the
idle

adjusting
screw
down

completely

Ooing
so
could
cause

damage
to

tip

which
in
turn
will
tend
to
cause

malfunctio11ll

b
If
idle
limiter

cap
obstructs

proper

adjustment
remove
it

To
install
idle
limiter

cap
refer
to

Idle
Limiter

Cap

c
After
idle

adjustment
has
been

made
shift
the
lever
to
the
N

or

P

position
for
automatic
trans

mission

d
When

measuring
CO

percentage
in
Engine
Fuel

b
Counties
1

219
m
4
000
ft
or

more
above
sea
level
have
been

designated
by
law
as

High
Altitude

Counties
For

further
details
refer

to
1977
OATSUN
PICK
UP
Service

Bulletin
Pub
No
257

0

I
Air
cleaner

rID
mOl

If
Low
altitude

Ll

n
n

L
n

Fig
EF
34

sert

probe
into
tail

pipe
more
than

40
em

15
7
in

CO
Idle

adjustment
with

CO
meter

Idle
mixture

adjustment
requires

the
use
of
a

CO
meter

especially
for

California
models
When

preparing
to

adjust
idle
mixture
it
is

essential
to

have

the
meter

thoroughly
warmed

up

and

calibrated

I

Check
carburetor

pipes
for

proper

connection

2
Warm

up

engine
until
water

tem

perature
indicator

points
to
the
middle

of

gauge
The

procedure
to
warm

up

engine
is
not

specifically
recom

mended
Either

driving
vehicle
or

oper

ating
engine
at

no
load
will

be

good

3
Make
sure
that
water

tempera

ture
indicator

points
to
the
middle

Further

keep

engine
running
at
about

2
000

rpm
for

about
5

minutes
with

out

applying
load
to

engine
in

order
to

stabilize

engine
condition

Engine

hood
should
be

open

4
Run

engine
for
about

10
minutes

at

idling
speed
Ouring
this
10

minutes

proceed
as
described
in

steps

5

to
9
below

5
Remove
air

hose
between
3

way

connector
5

way
connector
for
Cali

fornia
models
and
air

check
valve
as

EF
21
shown
in

Figure
EF
35

Plug
the
dis

connected
hose

to

prevent
dust

from

entering

0

o

EF259

Fig
EF
35
Disconnecting
air
hose

from
air
check
valve

6
Race

engine
I
500

to
2
000

rpm

two
or
three
times

under
no
load
then

run

engine
for
one
minute
at

idling

speed

7

Adjust
throttle

adjusting
screw

until

engine
is

at

specified
speed

Engine
speed

Manual
transmission

750

rpm

Automatic
transmission

in
0

position

650

rpm

8
Check

ignition
timing
If
neces

sary
adjust
it
to

specifications

This

operation
need
not
be
carried

out
at
1

600
Ian
1

000
miles
service

Ignition
timing

Manual
transmission

120
750
rpm
Non
California

100
750

rpm
California

Automatic
transmission

in
0

position

120

650

rpm

9
At

about
10
minutes

after

engine

is
run

at

idling
speed
adjust
idle

adjusting
screw
so

that
CO

percentage

is
at

specified
level

CO

percentage

Manual
transmission

2
t
l

at
750

rpm

Automatic

transmission

in
0

position

2
t
I
at
650

rpm

10

Repeat

procedures
as
described

in

steps
6

7
and
9
above

so
that
CO

percentage
is
at

specified
level
Check

ing
idle
CO
in

step
9
can

be
carried
out

right
after

step
7

II
Race

engine

1
500
to
2

000

rpm
two
or
three

iimes
under
no

load

and
make

sure
that

specified
CO

per

centage
is
obtained

12

Connect
air

hose
to
air

check

valve

If

engine
speed
increases

readjust
it

to

the

specified
speed
with
throttle

adjustingsqew

CO
idle
edJustment
without

CO
meter

If
CO

meter
is
not

available
the

following
procedures
may
be
used

L
Check

carburetor

pipes
for

proper

connection

2
Warm

up
engine
until
water

tem

perature
indicator

points
to
the

middle

of

gauge
The

procedure
to
warm

up

engine
is
not

specifically
recom

mended
Either

driving
vehicle
or

oper

ating
engine
at

no
load
will

be

good

3
Make

sure
that

water

temperature

indicator

points
to
the
middle

Further

keep
engine
running
at
about
2

000

rpm
for
about
5

minutes
without

applying
load
to

engine
in
order

to

stabilize

engine
condition

Engine

hood
should
be

open

4
Run

engine
for

about
10
minutes

at

idling

speed

During
this

10

minutes

proceed
as

described
in

steps

5
to

9
below

5

Remove
air

hose
between
3

way

connector
5

way
connector

for
Cali

fornia
models
and
air

check
valve

shown
in

Figure
EF

35

Plug
the
dis

connected
hose

19
prevent
dust
from

entering

6
Race

engine
1
500
to
2
000

rpm

two
or

three
times
under

no
load
then

run

engine
for

one
minute

at

idling

speed

7

Adjust
throttle

adjusting
screw
so

that

engine
speeds
are

as
indicated

below

Engine
speed

Manual
transmission

815

rpm

Automatic
transmission

in
D

position

670

rpm

8
Check

ignition
timing
if
neces

sary

adjust
it

to
the
value

required
by

specifications
This

operation
need

not

be
carried
out
at
1

600
km
1

000

miles
service

9
At
about

10
minutes
after

engine
Engine
Fuel

is

run
at

idling

speed
adjust
idle

adjusting
screw
until
maximum

rpm
is

obtained

10

Repeat
procedures
as
described

in

steps
6
7
and

9
above

until

engine

speed
at
best
idle
mixture
is
815

rpm

for

manual
transmission

models
and

670

rpm
for
automatic
transmission

models

in
D

position
Adjustment

in

step
9
can
be
carried
out

right
after

step
7

11
Turn
the

idle

adjusting
screw

clockwise
until

engine
speed
drops
off

below

specified

rpm

Engine
speed

drops
off

Manual
transmission

60
to
70

rpm

Automatic
transmission

in
D

position

15
to
25

rpm

12

Connect
air
hose

to
air

check

valve

If

engine
speed
increases

readjust
it

to
the

specified

speed
with

throttle

adjusting
screw

Idle
limiter

cep

Do
not

remove
this
idle

limiter

cap

unless

necessary
If
this
unit
is
re

moved
it
must

be

readjusted
at
lime

of

installation
To

adjust
proceed
as

follows

I

After

adjusting
throttle

or
idle

speed

adjusting
screw
check

to
be
sure

that
the
amount

of
CO
contained
in

exhaust

gases
meets

the
established

standard

2

Install
idle
limiter

cap
in

position

making
sure
that
the

adjusting
screw

can
rotate
another
1
8

turn
in

the

CO

RICH
direction

Carbo
to

per

CO

rich

450
lIS
rotation

t
CO
lean

J

SQ

dl
lim

ET031
1
e
Iter

cap

Fig
EF

36

Setting
idle
limiter

cap

FUEL

LEVEL

1

Turn

down
float

chamber
to
al

low
float
to

come
into

contact
with

needle

valve
and
measure

Hu
shown

EF
22
in

Figu
re
EF

37

When
H

is

approximalely
7

mill
0
283

in

lOp
float

position
is

correct

The

top
float

position
can

be
ad

justed
by

bending
float

seat

Upon
completion
of
the

adjust

ment

check
fuel
level
wi
th

attached

level

gauge

p

j

i

I

it

I
Float
seat

2

Float

3

Float
chamber

4
Needle
valve
t
I
IIf

ET032

Fig
EF
37

Adjusting
float
level

2

Adjust
bottom
float

position
so

that
clearance
h
between

float
seat

and
needle

valve
stemis
I

3
to
L
7

mm

0
051
to
0
067
in
when

Iloat
is

fully

rals
n

Jloa
t

goppe

q
re

3

After

adjustments
in

steps
I
and

2

above
have
been
made

make
sure

that

when
fuel
is

delivered
to
the
float

chamber

the
fuel
level
is
maintained

within
the

range
of23
mm

0
91
in

as

shown
in

FigureEF
38

H
23

mm
0
91
in

EF260

Fig
EF
38

Checking
ruellevel

FAST
IDLE

I
With

carburetor

assembly
reo

moved
from

engine
measure
throttle

valve

clearance
A

with
a

wire

gauge

placing
the

upper
side

of
fast

idling

screw
on
the
first

step
on
fast

idling

cam

Engine
Removal

Installation

ENGINE

REMOVAL
AND
INSTAllATION

REMOVAL

INSTALLATION

ENGINE
MOUNTING
INSULATORS

REMOVAL

It
is
much
easier

to
remove

engine

and
transmission

as
a

single
unit

than

to

remove
them

separately
After
re

moval

engine
can
be

separated
from

transntission

assembly

Notes

a
Be

sure
to
hoist

engine
and

jack
up

transmission
in
a
safe
manner

b
Use

fender
cove
to

protect
vehicle

body

1
Remove

battery

2
Scribe

hood

hinge
location
for

proper
reinstallation
and
remove

hood

Note
Have

an
assistant

help
you
so
as

to

prevent
damage
to

body

3
Drain

radiator
coolant

4

Disconnect

upper
and
lower

radiator
hoses

from

engine

5

Remove

two
oil
cooler
hoses

from
lower

end
of
radiator
Auto

ma
tic
transmission

models

only

6
Remove

radiator

shroud

7

Remove
four

bolts

securing
radia

tor
and

detach
radiator

Note

Always
tighten
securing
bolt
at

upper
right
hand
side

together
with

body
harness

terminal

8

Remove
carburetor
air

cleaner
as

follows

Remove
fresh
air

duct

Remove

hot
air

duct

Loosen
air

cleaner
band

bolt
and
air

cleaner

supporting
bolts

Disconnect
air

cleaner
ta
air

pump

hose

Disconnect
air
cleaner

to
rocker

cover
hose
at

rocker

cover

Disconnect
air

cleaner

to
air

control

valve
hose
California

models

only
CONTENTS

ER
2

ER
3

ER
3
FRONT

INSULATOR

REAR

INSULATOR

TIGHTENING

TORQUE
ER
4

ER
4

ER
4

Disconnect
air

deaner
to

A
B
valve

hose

Disconnect
air

cleaner
ta

vacuum

hoses

Note

Protect
carburetor
from
dust

and

foreign
matter

by

placing
cover

over
air
inlet

opening

9

Disconnect

fuel

pump
to
fuel

fdter
hose
and
return

hose

10

Disconnect
carbon
canister

hose

on

engine
side

II

Disconnect
air

pump
air

C1eaner

to
al

p

p
hose

12

Disconnect

following
cables

wires

and
hoses

Engine
ground
cable

Accelerator
wire
at

carburetor

High
tension

cable
between

ignition

coil

and
distributor

Wire

to
distributor
at

body
ter

minal

Wire
to

oil

pressure
switch

Wires
to
thermal

transmitter

Wires
to

B
C

p
D
cut
solenoid

Non
California

models

only

auto

choke
heater
and

anti

dieseling

solenoid

Wires

to
alternator

Wires
to
starter

motor

Heater
inlet
and
outlet

hoses
if
so

equipped

Vacuum
hose
of

Master
Vac
at
in

taJce
manifold

Wires
for

back

up

lamp
switch

Cable
to

speedometer

13

Remove
transmission

control

linkage
from

transmission

Manual

transmission
models

I

Detach
rubber
boot

2
Remove
E

ring
and
control

lever

pin
from

transmission

striking
rod

guide
and

remove
control
lever

ER
2
Fig
ER
l

Automatic

transmission
models

I

Disconnect

selector

range
lever

from
manual
shaft

2
Disconnect
wires

at
inhibitor

switch
and

down
shift
solenoid

14
Air

conditioner

equipped

models
need

following

procedures

1
After

removing
flexible

hose

support
remove
four

comi
ressor

se

curing
bolts

Then
move
the

com

pressor
to

battery

support

2

Remove

vacuum
hoses
of

F
LC
D
solenoid
valve

3
Remove
F
LC

D
actuator

15
Remove
two
bolts

securing

clutch

operating
cylinder
Then
dis

connect

operating
cylinder
and

flexi

ble
tube

as
an

assembly

Manual

transmission

models

only

16
Disconnect
front

exhaust
tube

from
exhaust
manifold

17
Remove

propeller
shaft

I

Disconnect

propeller
shaft

center

bearing
bracket
from

third

crossmember

2

Disconnect

propeller
shaft
from

companion
flange
of
differential

carrier

3
Remove

propeller
shaft
from

transmission

and

plug

up
rear
end
of

extension

housing
of

transmission
to

prevent
oil

leakage

18
Attach
a
suitable
wire

or
chain

to
lift

engine

19
Remove

front

engine
mounting

bolts

at

engine
mounting
front

sup

port

COWL
TOP
GRILLE

@
@

REMOVAL
AND

INSTALLATION

I

Open
engine
hood

2
Remove
two
windshield

wiper

blad

3

Remove
cowl

top

grille
attaching

HOOD

REMOVAL
AND

INSTALLATION

1

Place

protective
covers
over
front

fender
and
cowl

top

grille

2

Open
engine
hood
Mark

hinge

locations
on
hood
and
loosen
off
four

bolts

securing
hood
to
hood

hinge
Use

extra
caution

to
avoid

damaging

painted
surfaces
of
fender
and
cowl

top
grille

3

Remove

engine
hood

4

To
install
reverse
above

pro

cedures

ADJUSTMENT

Four

slotted
holes
in

hood

hinge

provide
for

fore
aft
and
side

adjust

ment

to
correct

space
between
hood

and
fender

and
hood
and

cowl

top

grille

Loosen

four
bolts

just
enough
to

move

engine
hood

and
move
hood
to

desired

position
if

necessary
to
correct

space

To
make
vertical

adjustment
adjust

height
of

dove
tail

bolt
at
hood

lock

male
until
hood
is
flush
with
fender
Body
Frame

1

Cowl

top
grille

2

Cap

3
Air
box
dtain
seal

4

Cowl

top

5

Air
box
drain

6
Screw

6F633

Fig
BF
13
Cowl

top
grille

screws
Pull

grille
straight
forward
to

remove

4
Remove
air

box
drain

5

To
install
reverse
above

steps

HOOD

Loosen
hood
to

hinge
bolts

just

far

enough
to
permit
movement
of

hood

2
Shift
hood
in

elongated
hole
until

parallel
space
is
reached
between
hood

and
fender
or
cowl

top
grille
Tighten

bolts

securely

BF

8
However

observe
the

following
items

I
When

installing
air
box
drain

apply
adhesive
to
its
lower
end

2

Align
cowl

top

grille
with
fend

ers

FRONT
FENDER

REMOVAL
AND

INSTALLATION

I

Remove
front

bumper

2
Remove
radiator

grille

3

Remove
front

apron

4
Remove
cowl

top
grille

S
Remove
hood

bumpers
two
on

each
side

6

Remove
nine

screws

attaching

front
fender
to
hood
ledge
See

Figure

BF
ll

7
To

install
reverse
above

steps

5

1
Female
lever

2

Safety
catch
lever

3
Return

spring

4
Dove
tail
bolt

S
Lock
nut

6
Hood
lock

pring

7

Spring
J

BF641A

Fig
BF
14
Hood
lock
male
and

female

j

I

8F635

Fig
BF
15

Engine
hood

alignment

WINDSHIELD
GLASS

DESCRIPTION

The

windshield

glass
is
retained
in

the

body
glass
opening
through
the

weatherstrip
There
are
twelve

water

drain
holes
one
on
each

side
of
the

bottom
of
the

glass
opening
and
ten

along
the

length
of
the

weatherstrip

1

Weatherstrip

2
Windshield

glass

3

Water
drain
hole

Fig
BF
35
Windshield

glass
and

weatherstrip
BF473A

REMOVAL

1
Place

protective
covers
over
en

gine
hood
front
fender
seat
and
in

strument

panel

2
Remove
inside
rearview
mirror

and
sun
visor

3
Remove
windshield

mouldings
if

so

equipped

4

Using
a

putty
knife
or
similar

flat
bladed
tool

pry
lips
of
weather

strip
out
of

place
from

top
and
side

flanges
of

body
opening

If

weatherstrip
is

to
be
reused
it
is

important
that
it

not
be

damaged

during
this

operation

BF041

Fig
BF
36

Removing
weatherstrip
Body
Frame

WINDSHIELD
GLASS

5

Working
from
inside
vehicle

push

windshield

glass
out

of

body

opening

by
hand

starting
at

right
and
left

upper
COIners
and

working
out
toward

ends

6
After

removing
weatherstrip
from

top
and
sides
of

body
opening
lift

glass

up
sufficiently
to

permit
removal

of

weatherstrip
from
bottom

flange

pry
weatherstrip
out
of

position

This

operation

requires
two
men

INSPECTION

Prior
to

installing
windshield

glass

make
the

following
checks
on
body

glass

opening
and

weatherstrips

I
Clean

weatherstrip
channels
re

placing
those
found
with

cracks
or

signs
of
deterioration

2
Clean

body
openings
noting
if

these
are
distorted
or
corroded

INSTALLATION

L

Fit

weatherstrip
on

glass

making

sure
it
is

properly
seated
and

posi

tioned
Adhesive
need
not
be

applied

0

BF641

Fig
BF

37

Fitting
weatherstrip
on

glass

2

Insert
a
draw
cord

completely

around

weatherstrip
outer
channel

Q
i

I

dYii

1

Windshield

glass

2
Draw
cord

3

Weatherstrip

Fig
BF

38
In8erting
draw
cord
around

weatherstrip
outer
channel
8F648

BF
16
3

With
aid
of
a

helper
press
wind

shield

assembly
against
body
opening

from
outside

being
sure
weatherstrip

lip
aligns
ith

body
opening
flange

4

Slowly

pull
cord
ends
from
inside

to

overlap
weatherstrip
channel
on

body
opening

flange
starting
at
center

top
and

working
out
toward
ends
This

operation
should
be
done
while
one

man
pushes

glass
against
body
opening

from
outside

The

same

technique
should
be

ap

plied
to

right
left
and
bottom

wea
th

erstrips

Fig
BF
39

Fitting
weatherstrip

top

BF650

Fig
BF

40

Fitting
weatherstrip

bottom

5
Install

windshield

moldings
on

weatherstrip
if
so

equipped

6
Install
inside
rearview
mirror
and

sun
visor

BACK
WINDOW

GLASS

AND
SIDE

WINDOW

GLASS

Refer
to
relative

topics
under
Re

moval

Inspection
and
Installa

tion
of
windshield

glass

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