1977 DATSUN PICK-UP coolant

Conventional

COUplin9

WATER
PUMP
SPEED

F

Z

Tern

coupling

WATER
PUMP

SPEED

C0029

Fig
CO
6
Characteristic

of

Tern
coupling

INSPECTION

Check
Tem

coupling
for
oil

leakage

or
bend
of
bimetal

If
the
above

symptoms
are
found

replace
it
with

a
new
one
as
an

assembly

THERMOSTAT

A
wax

pellet
type
thermostat
is

mounted
in
the
thermostat

housing
at

the

cylinder
head
water
outlet

The
function
of
the
thermostat
is

to
control
the

flow
of
coolant
facili

tating
fast

engine
warm

up
and

regu

lating
coolant

temperature
The
ther

mostat
is

designed
to

open
and
close
at

predetermined
temperatures
and
if

not

operating
properly
should
be

re

moved
and
tested
as
described
below

REMOVAL
AND

INSTALLATION

I

Drain
coolant

partially

2
Disconnect

upper
radiator
hose
at

water
outlet

3

Remove
bolts

and
remove
water

outlet

gasket
and
thermostat
from

thermostat
housing

Fig
CO
7

Removing
therm06t
t
Cooling
System

4

After
checking
thermostat
re

install
with

a
new

housing
gasket
in

place

5
Reinstall
water

outlet

6

Replenish
coolant
and
check
for

leaks

INSPECTION

A

sticking
thermostat
will

prevent

the

cooling
system
from

functioning

properly
If
the
thermostat
sticks
in

the

open
position
the

engine
warms

up
very
slowly
If
the
thermostat

sticks
in

the
closed

position
over

heating
will
result
Therefore
the
ther
mostat
should
be

inspected
to

make

sure
that
it
is
in

good
condition

1
Measure
coolant
temperature

when
thermostat
valve
starts
to

open

2
Measure
the
maximum
lift

of

thermostat
valve

Fig
CO
S

Impecting
therm06t
t

Temperate
Frigid
Tropical

type

type
iype

Valve

opening

80
5
to
83
5
86
5
to
89
5
75

to
78

temperature

177
to
183
187
to
193

167
to
172

oC
OF

Maximum

valve
lift
8
95
8
1
00
8
90

mm
oC

in
F
0
31
203

0
31
212
0
31

194

If
thermostat
does
not

operate
at

the
above

specified

temperature
it

must
be

replaced
because
it
cannot
be

repaired

RADIATOR

The
radiator
is

a
conventional
down

flow

type
having

top
and

bottom

tanks
to

distribute
the
coolant
flow

uniformly
through
the
vertical
tube
of

radiator
core

The

radiator
filler

cap
is

designed
to

maintain
a

pre
set

pressure
0
9

kg
cm2
13

psi
above

atmospheric

pressure

The
relief
valve

consisting
of

a

blow
off

valve
and
a

vacuum
valve

helps
to

prevent
the
coolant
from

boiling
by
giving

pressure
to
it
How

ever
when

the

pressure
is
reduced

below

atmospheric

pressure
the

vacu

um
valve
allows
air

to
re
enter

the

radiator

preventing
the
formation
of
a

vacuum
in
the

cooling
system

CO
5
On
models

equipped
with
auto

matic
transmission

the
oil
cooler
is

combined
with
the

radiator
to
cool

transmission
fluid

REMOVAL
AND

INSTALLATION

Drain
coolant
into
a
clean
con

tainer

2

Disconnect
radiator

upper
and

lower
hoses
On
models
with
auto

matic
transmissions
disconnect
cooler

inlet
and
outlet
lines
from
radiator

3

Remove
fan
shroud
retaining

bolts
and

remove
fan
shroud

4

Remove
front

grille

5

Remove
radiator
retaining
bolts

and
then

remove
radiator

upward

6
Install
radiator
in
the
reverse
se

quence
of
removal
Note
the
fol

lowing

I
Insert
hoses
in

their

positions

until

they
bottom

2
Ensure
that
arrow
marks
on

hoses
are

clearly
visible
from

upper

Condition

Loss

of
water

Poor
circulation

Corrosion

Overheating

Overcooling
Cooling
System

TROUBLE
DIAGNOSES
AND
CORRECTIONS

Probable
cause

Damaged
radiator
seams

Leaks
at
heater
connections
or

plugs

Leak
at

water

temperature
gauge

Loose

joints

Damaged
cylinder
head

gasket

Cracked

cylinder
block

Cracked

cylinder
head

Loose

cylinder
head

bolts

Restriction
in

system

Insufficient
coolant

Inoperative
water

pump

Loose

fan
belt

Inoperative
thermostat

Excessive

impurity
in

water

Infrequent
flushing
and

draining
of

system

Inoperative
thermostat

Radiator
fin
choked
with
mud
chaff
etc

Incorrect

ignition
and
valve

timing

Dirty
oil
and

sludge
in

engine

Inoperative
water

pump

Loose
fan
belt

Restricted
radiator

Inaccurate

temperature
gauge

Impurity
in

water

Inoperative
thermostat

Inaccurate

temperature
gauge

CO
7
Corrective
action

Repair

Repair

Tigh
ten

Tighten

Replace

Check

engine
oil
for
contamination
and
refill

as

necessary

Replace

Check

engine
oil
in
crankcase
for

mixing

with

water

by
pulling
oil
level

gauge

Replace

Tighten

Check
hoses

for

crimps
and

clear
the

system

of
rust
and

sludge
by
flushing
radiator

Replenish

Replace

Adjust

Replace

Use
soft
clean
water
Rain

water
is
satis

factory

Cooling

system
should
be

drained
and

flushed

periodically
Permanent
anti
freeze

Ethylene
glycol
base
can
be

used

through

out
the

seasons
of
the

year
and

change

periodically
at
intervals
recommended

Replace

Clean
out

air

passage
thoroughly
by
using
air

pressure
from

engine
side
of
radiator

Adjust

Refill

Replace

Adjust

Flush
radiator

Replace

Use
soft
clean
water

Replace

Replace

E
G
R
OFF

operation

When

engine
coolant

temperature

is
low

recirculated
exhaust

gas
causes

irregular
engine

operation
To

prevent
Emission
Control

System

this
recirculation

of
exhaust

gas
must

be
cut
off

for
a
few

minutes
after

engine
has
started
The
thermal
vacu

um
valve

is

provided
for
this

purpose

r
rn

11

L

e

7

E
G
R

controlval
le
clo

2

When

engine
coolant

temperature

is
above

the

working

temperature
of

the
thermal

vacuum
valve

I
The
valve

port
come

to
the

top

J
It
remains

closed
while

engine
coolant

temperature
is
low
and

keeps
the

E
G
R
control
valve
closed

thereby

culling
off
the

E
G
R
circuit

I

lW
jS

1
Throttle
valve

Thermal
vacuum

valve
close

j
Note

m
Vacuum
condition

of
the

throttle
valve
du

ring

engine

idling
for

improved
idling

operation

At

this

point
vacuum
does
not

actuate

the
E
G
R
control
valve

r
T
D

L

t

i

q

II

E
G
R
control

valve

close

2
In
the
full

throttle

driving
posi

tion

the
suction
vacuum

on
the
vacu
JllrI

Thermal
vacuum
valve

ope

um

passage
does

not

surpass
the
vacu

um

required
to

actuate
the
E
G
R

EC
20
EC227

Fig
EC
49
E
G
R
not

actuated

though
intake

manifold

vacuum
is

high
and
E
G
R

control
valve
remain

closed

l

Throttle
valve

EC228

Fig
EC
50

E
G
R
nol

actualed

control

valve

6

Thermal
vacuum
valve

Open

E
G
R
control
valve
Close

E
G
R
ON

operation

The
E
G
R
circuit
is

completed

only
when

engine
coolant

temperature
Emission
Control

System

I

I
Note
Vacuum
condition

EC793

Fig
EC
51
E
G
R
not
actuated

is
above
the

working
temperature
of

the

thermal
vacuum
valve
and
carbu
retor
suction
vacuum
is

large
enough

to

open
the
E
G
R

control
valve

Y
m
l

fj

t1f
1t
3
0

l

P
@
0
f
Y
f

1
i0
W
g

1
i3
iiA
d

m

E
N
ti

n
k

i

l
i
Throttle
valve

n

L
r

E

G
R

control
valve

Open

E
G
R
control
valva

The

E
G
R

control
valve
controls

the

quantity
of
exhaust

gas
to
be
led

to
the

intake
manifold

through
vertical

movement
of
the

taper
valve
connect

ed

to
the

diaphragm
to
which

vacuum
Thermal
vacuum

valve

Open

Note

iiiI
Vacuum
condition

EC794

Fig
EC
52
E
G
R
actuated

is

applied
in

response
to
the

opening

of
the
carburetor
throttle
valve
The

E
G
R
control
valve
is
installed
on
the

E
G
R

passage
through
a

gasket

E
G
R
con
trol
valve
construction

and

type
vary
with

transmission

type
and

car
destination
For
identification

purposes
the

part
number
is

stamped

on
the
recessed

portion
at
the

top
of

the
valve

The

construction
of
the
E
G
R

control
valve
is

shown
below

EC
21

1

1

I
I

I

1
v

v

I
I

I
I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

L
0

I

Magnet
coil

Detector
drive

counter

REMOVAL
AND

INSTALLATION

Remove
air
cleaner

before

removing

E
G
R
control

system
For
removal

and

installation
of
air

cleaner
refer
to

Air
Cleaner
section

Page
EF
S

Removal

I
E
G
R
control
valve

After

removing
the

following
parts

the
E

G
R

controi
valve
can

be
dis

mounted

Vacuum

hose
thermal
vacuum

valve
to
E
G
R

control
valve

E
G
R
control
valve

mounting
nut

Note
To
remove

vacuum
hose
flat

ten

clip
connecting
vacuum
hose
to

E
G
R
control
valve
and

pull
the

hose
off
with
hand
Emission
Control

System

Ignition
switch

E
G
R

warning
lamp

f

1
Ignition
switch

start

position

Fuse

1
A
Odometer
switch

r

I
I

I

I
v

I

I
I

i

lQ
U

1

mi

L
J

EC233

Fig
EC
55
E
G
R

warning
circuit

EC234

Fig
EC
56

Removing
KG
R
control

valve

2
E
G
R

pass
ge

After

removing
the

following

parts

the
E
G
R

passage
can
be
dismounted

Exhaust
gas
return

tube
exhaust

manifold

to
E
G
R

passage

B1ow

by
hose

cylinder
block

to

P
C
v
valve

Vacuum
hose
AB
valve
to
E
G
R

passage

E
G
R

passage
mounting
bolt

EC

23
EC541

Fig
EC
57

Removing
E
G
R

passage

3

Thermal
vacuum

valve

After

removing
the

following

parts

the
thermal
vacuum
valve
can
be
dis

mounted

Vacuum
hose

carburetor
to
ther

mal
vacuum
valve

Vacuum
hose
thermal
vacuum

valve

to
E

G
R
control
valve

Note
Drain

engine
coolant
before

dis

mounting
thermal
vacu
m
valve

Fig
EC
58

Removing
thermal

vacu
um
valve

Ignition
Switch
Position
START

Detector
Drive

Counter

E
G
R

Warning
Lamp
ON

b
After

completing
inspection
of

E

G
R

control
system
be

sure
to

reset

odometer
of
detector
drive

counter
to

zero

c
This
item

applies
to
all
620
models

except
those
bound
for
California

and
Canada

3

With

engine
stopped
inspect

E
G
R
control
valve
for

any
indication

of

binding
or

sticking
by
moving
dia

phragm
of
control
valve

upwards
with

a

finger

2
When

engine
coolant

tempera

ture
is

high

I
Make

sure
that
E

G
R

control
valve

operates
when

engine
speed
is
in

creased
from
idling
to
3
000
to

3
500

rpm
Place
a

fmger
on
the

diaphragm
of
E
G
R
control

valve

to
check
for
valve

operation

2
If

E
G
R
control
valve
does
not

operate
check

as
follows

Disconnect
one
end
E

G
R
control

valve
side
of
vacuum
hose
connect

ing
thermal
vacuum
valve
to
E
G
R
Emission
Control

System

ON

Below

50
000
counts
Above

50
000
counts

OFF
ON

4
With

engine
running
inspect

E
G
R

control
valve
and
thermal
vacuo

um
valve
for
normal

operation

1
When

engine
coolant

tempera

ture

is
low

Make

sure
that
E
G
R

control
valve

does
not

operate
when

engine
speed
is

increased
from

idling
to
3
000
to

3
500

rpm

Place
a

fmger
on
the

diaphragm
of

E
G
R
control
valve
to

check
for
valve

operation

EC253

Fig
EC
62

Checking
E
G
R
control
valve

control
valve

Increase

engine
speed
from

idling
to

3
000
to
3

500

rpm

Make
su
re
that
thermal
vacu
um

valve
is

open
and
that

carburetor

vacuum
is

present
at
the
end

E

G
R
control

valve
side
of

vacu

um
hose

If
vacuum
is
weak
or

not

present
at

all

replace
thermal
vacuum
valve
If

vacuum
is

present
replace
E
G

R

control
valve

EC
25
EC254

Fig
EC

63

Checking
lhermal

vacuum
valve

If

any
difficulty
is
encountered
in

judging
the
condition
of

any

compo

nent

during
above

inspection
check

the

questionable
component
independ

ently
as

follows

E
G
R

control
valve

Dismount
E

G
R

control
valve

from

engine

I

Apply
vacuum
to

E
G
R

control

valve

referring
to
the

following
figure

If

the
valve

moves
to
full

position
it
is

normal

E
G
R

control
valve
will
remain

open
for
more

than
30

seconds
after

vacuum
has
cut

off

la

ET152

Fig
EC
64

Checking
E
G
R

control

ualue

2

Visually
check
E
G
R

control

valve
for

damage
wrinkle
or
defonna

tion

3

Clean
the

seating
surface
of

E
G
R
control
valve
with
a
brush

and

compressed
air

and
remove

foreign

matter
from
around
the
valve
and

port

EC350

Fig
EC
65

Cleaning
E

G
R
control

valve

Thermal

vacuum

valve

Dismount
thermal

vacuum
valve

from

engine

Note
Before

dismounting
drain
en

gine
coolant

from

engine

Apply
vacuum
to
thermal
vacuum

valve
and

check
to
be
sure
thaI
ther

mal
vacuum
valve

opens
or
closes
in

response
to

engine
coolant

tempera

ture
as

specified

Thermal
vacuum
valve

should

open

at
a

temperature
of
57
to
630C

135

to
1450F

completing
the

vacuum

passage

Note
Do

not
allow
water
to

get

inside

the
thermal
vacuum
valve

EC242

Fig
EC
66

Checking
hennal

vacuum

valve
Emission
Control

System

CATALYTIC

CONVERTER

DESCRIPTION

The

catalytic
converter
accelerates

the
chemical
reaction
of

hydrocarbons

HC
and
carbon
monoxide
CO
in

the

exhaust

gas
and

changes
them
into

non
harmful

carbon
dioxide

C02

OPERATION

Exhaust

gas
emitted

from
the
en

gine
contains

some
harmful
substances

due
to

incomplete
combustion
in
the

combustion
chamber
The

air

injection

system
is

designed
to

reduce
the
con

tent
of
such
substances
in

the
exhaust

gas
In

this

system
the

secondary
air

is

led
from
the
check
valve

and

injected

into
the

exhaust
manifold

With
this

injection
of
the

secondary
air

hydro

EC444

EC
26
and
water

H20
This
chemical
reac

tion

process
requires
the

proper
a

mount

of
air

which
is

supplied
by
the

air

pump
Refer
to

the
item
AJ

S

This
air
is
caUed

secondary
air

The

catalytic
converter
is
mounted

on
the

vehicles
destined

for
California
Refer

to

Figure
EC
67

3
4

1
Front
tube

2

Catalyti
converter

3
Center
tube
4
Main
muffler

5
Rear
tube

EC782

Fig
EC
67

Location

of
catalytic
converter

car

ons

He
and
carbon

monoxide

CO
in
the
exhaust

gas
are

gradually

oxidized
with

oxygen
02
in
the

secondary
air
and
converted

into
non

harmful
carbon

dioxide

C02
and

water

H20

The

catalytic
converter

further

cleans

engine
exhaust

gas
Through

catalytic
action
it

changes
residual

hydrocarbons
and
carbon
monoxide

contained

in
exhaust

gas
into
carbon

dioxide

and
water
before

exhaust

gas

is

discharged
to
the

atmosphere

c
Secondary
air

Carbon
monoxide

hydrocarbon

Carbon
dioxide
gas

water

F
EC
68

Operution
of
catalytic
corwerter

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