1977 DATSUN PICK-UP cooling

General
Information

APPROXIMATE
REFILL
CAPACITIES

I
Uter
u
s

measure

Imper
measure

Fuel
tank

I
45
J
IUi

gal
9

Ji

gal

Cooling
system
ManUal
transmission

I
8

0J

I
8Jiqt
7

qt

with
heater

Automatic
tr
smission

I
7

8J

I
8Y

qt

6Jiqt

Engine
lubrication
with
oil

f1lter

I
4

3J

I
4
Ji

qt
3

qt

system

without
oil
f1lter

I
3

8J

I
3Xqt
4

ql

I
4

speed
transmission

I
1

7J

I
3X

pl
3

pI

Manual
transmission

I
5

speed
transmission

I
2
0

I
4Y

pt
3Mpt

Automatic
transmission

I
5
s
J

I
5Uqt
4Uqt

Steering

gear
box

I
0
33J

I
pt
pt

Differential

carrier

I
1
0
J

I
2M

pI
I

pt

RECOMMENDED
FUEL

Use

an
unleaded
or
low
lead

gasoline
with
a
minimum
octane

rating
of
91

RON
Research

Octane

Nuniber
For
California

models
use
only
unleaded

gasoline
to

protect
the

catalytic
converter
from
contamina

tion

RECOMMENDED

LUBRICANTS

RECOMMENDED
SAE

VISCOSITY

NUMBER

C

ENGINE

on

12O
II
O
10Vt4ll
10Wf
2

I
ICWI
I

ao
40

J

SAE
5W
20
oils

ate
not
lecom

mended
for
sustained

high
speed

drivin

GEAR
On

I

J

w

c

30
20
0

20
40
60
80
100

Temperature
Range

Anticipated
Before

Next
Oil

Change
OF

GI
8

Engine
Tune

up

BASIC
MECHANICAL
SYSTEM

ADJUSTING
INTAKE
AND
EXHAUST

VALVE
CLEARANCE

CHECKING
AND

ADJUSTING
DRIVE

BELT

RETIGHTENING
CYLINDER
HEAD
BOLTS

MANIFOLD
NUTS
AND
CARBURETOR

SECURING
NUTS

CHECKING
ENGINE
OIL

REPLACING
OIL
FILTER

CHANGING
ENGINE

COOLANT

ADJUSTING
INTAKE

AND

EXHAUST

VALVE
CLEARANCE

Note
After

tightening
cylinder
head

bolts

adjust
intake

and
exhaust

valve
clearances

Valve
clearance

adjustment
is

impossible
when
the

engine
is
in

oper

ation

1
Loosen

pivot
locking
nu
t
and

turn

pivot
screw
until
the

specified

clearance
is
obtained
while
cold

Using
service

tool

tighten
pivot

locking
nut

securely
after

adjustment

and
recheck
the
clearance

2
Warm

up
engine
for
at
least

several
minutes

and

stop
it
Measure

valve
clearance
while
hot
If
out
of

specifications
adjust

Unit
mm
in

Intake
0
20

0
008

Cold

Exhaust
0
25
0

010

Intake
0
25

OmO

Wann

I
Exhaust

0
30
0

012

STl
064000

I

ET009

Fig
ET

5

Adjusting
valve

clearance
CONTENTS

ET
7
PERMANENT
ANTI
FREEZE

COOLANT

CHECKING
COOLING
SYSTEM
HOSES

AND
CONNECTIONS

INSPECTION
OF

RADIATOR
CAP

COOLING
SYSTEM
PRESSURE
TEST

CHECKING
VACUUM

FITTINGS
HOSES

AND
CONNECTIONS

CHECKING
ENGINE
COMPRESSION

COMPRESSION
PRESSURE
TEST

TEST
RESULT
ET
7

ET7

ET
B

ET
B

ET
B

CHECKING
AND

ADJUSTING

DRIVE

BELT
ET

B

ET

B

ET
B

ET
B

ET

B

ET
9

ET
9

ET
9

2

Normal
drive
belt
deflection
is

8

to
12
mm

0
315
to
0
472

in
when

moderate
thumb

pressure
is

applied

midway
between

pulleys

1
Check
for

cracks
or

damage
Re

place
if

necessary

Compressor
pulley

8
to
12
mm
0
315
to
0
472
in

Idler

pulley

Water

pump
pulley

8
to
12
mm

0
315
to
0
472
in

Air

pump
pulley

Alternator

AC456

Fig
ET
6
Driue
belt
tension

RETIGHTENING

CYLINDER
HEAD

BOLTS
MANIFOLD

NUTS
AND

CARBURETOR

SECURING

NUTS
Tightening
torque

Cylinder
head
bolts

1st

turn

4

0

kg
m
29
ft
Ib

2nd
turn

6
0

kg
m

43
ft
Ib

3rd
turn

6
5
to

8
5

kg
m

47

to
61
ft
lb

Refer
to
the

following
tightening

torque
specifications

ET
7

r

ManifolJ
nuts

I

2
to
1
6

kg
m

8
7
to
I

6
ft
lb

Carburelor
nuls

0
5
to
1
0

kg
m

3
6
to
7
2
fl
tb

Fig
ET
7
Tightening
s

quence

CHECKING
ENGINE

OIL

Check
if
oil
is
diluled
with
water

or

gasoline
Drain
and
refill
oil
if

necessary

Notes

a
A

milky
oil
indicates
the

presence

of

cooling
water
Isolate
the
cause

and
take
corrective
measure

b
An
oil
with

extremely
low

viscosity

indicates
dilution
with

gasoline

2
Check
oil
level
If
below
the

specified
level

raise
it

up
10
the
H

level

Engine
oil

capacity

including
oil

filter

Maximum
H
leven

4
3
liters

4

MUS
qt
3
Y

Imp
qt

Minimum
L

level

3
3
liters

3
f
US

qt
2
U

Imp
ql

REPLACING
OIL

FILTER

The
oil
mter
is

a

cartridge
type
and

can
be
removed

using
Oil
Filter

Wrench
STI9320000

I
Check
for
oil
leaks

past
gasketed

flange
If

leakage
is

found

retighten

just
enough
to

stop
leakage
If

retight

ening
is

no

longer
effective

replace

mter
as
an

assembly
Engine
Tune

up

2
When

installing
oil

filter

tighlen

by
hand

Note
Do
not

overtighten
oil

flIt

lest

leakage
should
occur

CHANGING
ENGINE

COOLANT

PERMANENT
ANTI
FREEZE

COOLANT

Permanent
anti

freeze
coolant
is
an

ethylene
glycol
base

producl
conlain

ing
chemical
inhibilors
10

protect
the

cooling
system
against
corrosion

The
anti
freeze
does
not
contain

any

glycerine
ethyl
or
methyl
alcohol

It
will
not

evaporate
or
boil

away
and

can
be
used
with
either

high
or
low

temperaturethennoslat

It

flows

freely
transfers
heat
effi

ciently
and
will

not

clog
passages
in

the

cooling
system

The
anti
freeze
must
not
be
mixed

with
other

products

This
coolant
can
be
used

through

out

the
seasons
of
the

year

Whenever
coolant
is

changed
the

cooling

syslem
should
be
flushed
and

refilled
with
a

new
coolant

Check
the
level
See
the
instruc

lions
furnished

by
the
manufacturer

for
the
mixture
ratio

of
anti
freeze
10

water

CHECKING

COOLING

SYSTEM
HOSES

AND
CONNECTIONS

Check
hoses
and

fittings
for
loose

connections
or
deterioration
Re

tighten
or

replace
if

necessary

INSPECTION
OF

RADIATOR

CAP

Apply
reference

pressure
0
9

kg
cm2
13

psi
1
to
radiator

cap
by

means
of

a

cap
tester
to
see
if
it
is

satisfactory
Replace
cap
assembly
if

necessary

ET
8
Fig
ET
fJ

Teltill
l
rod
ioto

cop

COOLNG
SYSTEM

PRESSURE
TEST

With
radiator

cap
removed

apply

reference

pressure
1

6

kg
cm2
23

psi
to
the

cooling
system
by
means

of
a
lesler
to
detect

any
leakage

Water

capacity

Without
heater

7
4
liters

7
U
US

qt
6
f

Imp
qt

With
heater

8
0
liters

8
f
US

qt
7

Imp
qt

CHECKING
VACUUM

FITTINGS
HOSES

AND
CONNECTIONS

Check
the
condition
of

filtings
and

hoses

Retighten
or

replace
if
neces

sary

All
vacuum
hoses
can
be
identified

by
colors

White
line

Vacuwn
tube
to
carburetor
E

G
R

Tube

Vacuum
tube
to
thermal
vacuum

valve

Thennal
vacuum
valve
to
E
G
R

control
valve

Engine
Tune

up

SERVICE
DATA
AND

SPECIFICATIONS

Ignition
timing
and

idling

Manual
transmission

Automatic
transmission

in
D

position

Valve

clearance

Cold
Intake

Exhaust

Intake

Exhaust
Hot

Belt
tension

Fan

Air

pump

Air

coo

compressor

Pressure

Compression
pressure
at
350

rpm

Standard

Minimum

Radiator

cap
relief

pressure

Cooling
system

Leakage
testing
pressure

Battery
specific

gravity
at
200C
680F

Distribu
tor

Point

gap

Air

gap

Dwell

angle

Condenser

capacity

Condenser
insulation

resistance

Spark
plug

Gap
degree
rpm
120
B
T
D

C
j750
Non
Calif

models

100

B
T
D

C
j750
California
models

degree
rpm
l20B

T
D

C
j650

mm
in

mm
in

mm
in

mm
in
0
20
0
008

0
25

0
010

0
25
0
010

0
30
0
012

mm
in

mm
in

mm
in

kg

lb
8
to
12
0
315
to
0
472

8to
12
0
315

to
0
472

8

to
12
0
315
to

0
472

10
22
is

applied

kg
cm2

psi

kg
em2

psi

kg
em
2

psi
12
0

171

9
0
128

0
9

13

kg
cm2

Psi
1
6
23

1

26

mm
in

mm
in

degree

IF

Mil
0
45
to
0
55
0

018
to
0
022

0
2
to
0
4
0

008
to
0
016

490
to
550

0
20
to
0
24

5

mm

in
0
8
to
0
9
0
031
to
0
035

Breaker

points
type

1

0
to
1
1
0
039

to
0
043

Transistor
ignition
type

Checking
CO

percent
at

idling
speed
No
air

Manual
transmission
model

rpm

Automatic
transmission
model

rpm

Adjustment
of

operating
pressure
of
B

C
D
D

B
C
D
D

set

pressure

Manual
transmission

Automatic

transmission
2
1

1
750

2
1
1
650

mmHg
in

Hg

mmHg
in
Hg
510
to
550
20
1

to
21
7

490
to
530
19
3
to
20
9

ET
25

Condition

ENGINE
POWER
NOT

UP
TO
NORMAL

Low
compression

Ignition
system
out
of

order

Fuel

system
out

of

order

Air
intake

system
out

of
order

Emission
control

Overheating

O

cooIing

Others
Engine
Tune

up

Probable
cause

Incorrect

iSnition
timing

Damaged

spark
plugs

Worn
distributor

points

Malfunction
of
choke

system

Clogged
fuel

pipe
or

floating
valve

Dirty
or

clogged
fuel
strainer

Fuel

pump
will
not
work

properly

C10ssed
carburetor

jets

Malfunction
of
altitude

compensator

CIOJBed
air
cleaner

Ail

inhaling
from
manifold

gasket
or

carburetor

gasket

Malfunction
of

E
G
R
valve

Stick
E
F
E

valve
shaft

Insufficient
coolant

Loose
fan
belt

Worn
or
oiled
fan
belt

Inoperative
thermostat

Worn
water

pump

Clogged
or

leaky
radiator

Worn
radiator
filler

cap

Ail

in

cooling
system

Improper
engine
oil

grade

Incorrect

ignition
timing

Clossed
carburetor
lean
mixture

Disconnected
altitude

compensator
hOlle

Inoperative
thermostat

Improper
octane
fuel

L

j
tire

pressure

Dragging
brake

Clutch

slipping

ET

30
Corrective
action

Previously
mentioned

Adjust

Clean

adjust
or

replace
plull

Dress

or

replace
points
Also
check

condenser

Adj
lst

Clean

Replace

Repair
or

replace

Disassemble
and
clean

Check
and

replace

Replace
element

Replace
gasket

Check
and
replace

Repair

Replenish

Adjust
fan
belt

Replace

Replace

Replace

Flush

repair
or

replace

Replace

Retighten
each

part
of

cooling
system

Replace
with

proper
grade
oil

Adjust

Overhaul
carburetor

Connect

Replace

Replace
with

specified
octane
fuel

Inflate

to

specified

pressure

Adjust

Adjust

Except
transistor

ignition
system

Engine
Mechanical

GENERAL
DESCRIPTION

MODEL

L20B
ENGINE

CYLINDER
BLOCK

CRANKSHAFT

PISTON
AND
CONNECTING
ROD

CYLINDER
HEAD
CONTENTS

EM
2

EM
3

EM
3

EM
3

EM
3
CAMSHAFT

VALVE
MECHANISM

CAMSHAFT
DRIVE

MANIFOLDS

out
smooth

dependable

power

The

cylinder
block
is
cast
as
a

single

unit

and

featllres
deep
skirting
This

engine
is

equipped
with
a

single
2

barrel
downdraft
carburetor
that
in

corporates
a

special
device
to
control

emissions
MODEL
L20B

ENGINE

The
L20B

engine
features
O
H
C

valves

wedge
shaped
combustion

chamber
aluminum
head
and
a

fully

balanced
5

bearing
crankshaft
to
turn

Main

specifications

Oisplacemen
t
cc

cu
in

Bore
x
stroke

mm
in

Compression
ratio

Ignition

timing

Degree
B

T
O
C

rpm
MIT

AlT

MIT
Manual
Transmission
EM535

Fig
EM
Cross
sectional
view

L20B

1

952
1191

85

X
86

3
35
x
3
39

8
5

12
750

Non
California

model

10
750

California

model

12
650
in
0
position

AIT
Automatic
Transmission

EM

2
EM
3

EM
3

EM
3

EM
3

CYLINDER
BLOCK

The

cylinder
block
a
mono
block

special

casting
structure

employs
a

five
bearing

support

system
for

quiet

ness

and

higher
durability

The

cylinder
bores
are
surrounded

by
cooling

jackets
and
machined
di

rectly
in
the
block
The
oil

ways
in
the

block

are
arranged
so
that
the

full
flow

oil
filter
is

directly
attached
to
the

right
hand
side
of
the
block

EM536

Fig
EM

2
Cylinder
block

CRANKSHAFT

The
crankshaft
is

a

special
steel

forging
Fully
balanced
it
turns
out

smooth

dependable
power
at

high

speed

The
L20B

engine
uses

eight
balance

weights

Main

bearings
are
lubricated

by
oil

pumped
through
the
main
oil

gallery

and
the
oil
holes
which
run
in

parallel

with

cylinder
bores
There

are

oilways

drilled
in

the
crankshaft
for
the
lubri

cating
oil
The
center
main

bearing
is

equipped
with
thrust
washers

to
take

up
end

thrust
of
the
crankshaft

Fig
EM

3

Crankshafl

PISTON

AND

CONNECTING
ROD

The

pistons
are

of
a

special
alumi

num

casting
and
have

struts
to
control

thermal

expansion
two

compression

rings
and

one
combined
oil

ring
The

piston
heads

are
slightly
dished

The

piston
pil1S
are
a

special
hollow

steel

shaft

They
are
full

floating
fit
to
the

piston
and

press
fit
to
the

connecting

rods

The

connecting
rods
are
of
a

special

forged
steel
Oil
is

sprayed
to
the

connecting
rod
small
ends

through

drilled

passages
in

the

large
ends
of

rod

Oil
holes
in

the

connecting
rods

are
located
so
as
to
insure

optimum

lubrication
under

heavy
load

0
50
1

o

E

Moao

Fig
EM
4

Piston
and

connecting
rod

CYLINDER
HEAD

The

cylinder
head
is

made
of
a

light
strong
aluminum

alloy
with

good

cooling
efficiency
it
contains

wedge

type
combustion
chambers
A

special

aluminum
bronze
valve
seat
is

used
on

the
intake
valve
while
a
heat
resistant

steel
valve
seat
is
installed

on
the

exhaust
valve
These

parts
are

all
hot

press
fitted

EM407

Fig
EM
S

Cylinder
head
Engine
Mechanical

CAMSHAFT

The
camshaft
is

made
of
a

special

cast
iron
and
is
loca
ted
inside
the

rocker
cover
Four
aluminum

alloy

brackets

support
it
Camshaft

bearings

are
lubricated
from
oil
holes
which

lead
to
the

main
oil

gallery
of
the

cylinder
head

Concentric

passages
are
drilled
in

the

front
and

rear

parts
of
the

earn

shaft

Oil
to
each
earn
lobe
is

supplied

through
an
oil

hole
drilled
in
the
base

circle
of
each
lobe
Lubricant
is

sup

plied
to
the
front
oil

gallery
from
the

2nd
camshaft

bearing
and
to
the

rear

oil

gallery
from
the

3rd
camshaft

bearing
These

holes
on
the
base

circle

of
the

lobe

supply
lubricant
to
the

earn

pad
surface
of
the
rocker
arm

and

to
the
valve

tip
end
The
cams
feature

a

long
overlap
profile
to
reduce
NOx

emission

Fig
EM
6

Camshafl

VALVE
MECHANISM

The
valve

system
has
the

pivot
type

rocker

arms
that

are
activated

directly

by
the
earn
mechanism

this
has
made

its

moving

parts
considerably
lighter

and

provides
ideal

high
speed
perform

ance

Dual

type
valve

springs
are
in

stalled

h

@l

if

Exhaust

Intake
EM084

Fig
EM
7
Valve
mechanism

EM

3
CAMSHAFT
DRIVE

The
camshaft
is
driven

by
a
double

row
roller
chain
driven

by
the

crank

shaft
The
tension
of
the

chain
is

controlled

by
a

chain
tcosioner

which

is

operated
by
spring
and
oil

pressure

The
rubber
shoe

type
tensioner

damps

vibration

of
the

chain
and
controls
its

tension

EM537

Fig
EM

8
Chain

driving

aystem

MANIFOLDS

The
intake
manifold
is
of
an
alumi

num
cast

alloy

The
exhaust
manifold
is

of
a
dual

design
and

incorporates
a
heat
control

valve
in
it
The

heal
control
valve
is

used
to

warm
the
intake
manifold

A

plate
is
installed
on
the
outer

face
of
the
manifold
to
draw
hot

intake
air

out

through
it
The
exhaust

pipe
is
connected
to
the

flanged
sur

face
of
the
exhaust
manifold

Fig
EM

9
Intak
and
exhaust

manifolds

r

I

I

PRELIMINARY
CLEANING
AND

INSPECTION

DISASSEMBL
Y

PRELIMINARY

CLEANING
AND

INSt

ECTION

Before

disassembling

engine
note

the

following

I
Fuel

oil
or
water

may
leak

past

cylinder
head
and
block
Prior
to

disassembling
check

cylinder
head

1
1ltermal
vacuum
valve

2
Check

valve

3
Altitude

compensator

in

air
cleaner

4
Air

gallery
pipe

S

Auto
choke

6
Automatic

temperature

control
air

cleaner

7
Anti
8ackfire
valve
A
B

valve

8
Boost
Controlled

Deceleration

Device
Bee
D
D

9
P
c
v

valve

to
Air
relief
valve

11
E

G
R

control
valve

12
B
C
D
D

control
valve
and

solenoid
valve

13

Emergency
air

relief
valve

14
Air

pump
air
cleaner

IS
Carbon
canister

16
Air
control

valve

11
Air

pump
Engine
Mechanical

ENGINE

DISASSEMBLY

CONTENTS

EM
4

EM
4
PISTONS
AND
CONNECTING
RODS

CYLINDER

HE
AD
EM
7

EM
7

front
chain

cover
oil

pan
and
oil

filter

gaskets
lInd
crankshaft
and
water

pump
seals
for

signs
of

leakage
past

their

gasketed
surfaces

2
Check
carburetor
and

fuel

pump

for
condition
fuel
hoses
for

deteriora

tion
cracks

or

leakage
of
fuel

past

their

jointed
or
connected

surfaces

Fig
EM

0
Emiuion
control
devic
s

California
mod
18
E
T366

3
Remove

carburetor
air

cleaner

Remove
fresh

air
duct

Disconnect
hot
air
duct
from

air

cleaner

Disconnect
air

cleaner
to
air

pump

hose
at
air

cleaner

Disconnect
air

cleanef
to
rocker

cover

hose
at
rocker
cover

Disconnect

air
cIeaner

to
air

con

trol

valve
hose
at
air

cleaner
Cali

fornia

models

only
Disconnect
air

cleaner
to
A

B
valve

hose
at
air

cleaner

Disconnect
air

cleaner
to

related

part
vacuum
hoses
at
air

cleaner

Loosen
air

cleaner
band
bolt
and

remove
carburetor
air

cleaner
as

sembly
from

carburetor

4

Plug
up
carburetor
air

horn

to

prevent
entry
of

foreign
matter

5

Remove

alternator
drive

belt

alternator
and

alternator
bracket

EM
4
6

Remove
air

pump
drive

belt
cool

er

compressor
and
idler

pulley
if

so

equipped

7
Remove
starter
motor
from
trans

mission

8

Visually

inspect
cylinder
head

cylinder
block
rocker
C
Ner

front

chain
cover
oil

pan
and
all
other
outer

parts
for
oil
water
and
fuel
leaks

breakage
or

missing
parts
such

as
bolts

and
nuts

9

Check

piping
and
electrical
cir

cuits
for
deterioration

breakage
fit

tings
discontinuity
or
insulation

DISASSEMBLY

To

remove

engine
from
vehicle

refer
to

the
instructions
under
the

Engine
Removal

and
Installation

ER
section

I

Remove
transmission
from

en

gine

2
Remove

clutch

assembly
from

flywheeL

3

Thoroughly
drain

engine
oil
and

coolan
t

by

removing
drain

plugs

Store

engine
oil
and

coolant
if

they

are

to
be

used

again

4
Place

engine
assembly
on

engine

stand

I

Remove

cooling
fan

2

Remove

right
engine

mounting

bracket

3

Remove
oil
filter
with
Oil

Filter

Wrench
STI9320000

4

Remove
oil

pressure
swi

tch

5

Install

engine
attachment
to

cylinder
block

utilizing
bolt

holes
in

alternator

bracket
and

water
drain

hole

6
Set

engine
on
stand

Engine
Attachment

ST05260001

Engine
Stand

ST050I

SOOO