air condition DATSUN PICK-UP 1977 Manual Online

Probable
cause

I
Air

leakago
at
check
valve

2
Air

leakage
a

t

push
rod
seal

3

Air
leakage
between
valve

body
and

seal

4
Air

leakage
at
valve

plunger
seat

5

Damaged
piping
or

joints

2
Fifteen

seconds
after

engine
is

stopped
and
brake

fully
applied
ob

serve
the

rate
of

drop
in
air

pressure

registered
by
vacuum

gauge

Probable
cause

1
Air

leakage
at
check
valve

2

Damaged
diaphragm

3
Reaction
disc

dropped
off

4
Air

leakage
at

and
valve
body
poppet
assembly
seat

Note
When

replacement
of

any
part

is

required
be
sure
to
renew

Master

Vac
as
an

assembly

Inspecting
check
valve

Remove

clip
and
disconnect
hoses

at
connections

The
check
valve

can

now
be
removed

yr

BA3

Fig
BR
26
Location

of
check
valve

2

Using
a
Master

Vac
tester

apply
a

vacuum

pressure
of

200

mmHg
7
87

inHg
to

the

port
of
check

valve
on
the

Master
Vac
side
If
a

pressure
drop
of

10

mmHg
0
39

inHg
is
exceeded
in
1

I

I

17
I

f
I

I
I

Z
I

I
y1
I

I
I
7
I
I
I

I
I
I

I
I
I

I

y1
II

I

I
I
I
I
I

I
L
I
L

5
to
15

20
25
30
35
40

45
50

55
60

22
44

66

88
110
132

Pedal

operating
force

kg
lb
BR772

Fig
BR
28

Performance
curves

of
Master
Vac
Brake

System

Corrective
action

Replace
check
valve

Replace
seal

Repair
or

replace
faulty

partes

Repair
or

replace
seat

Repair
or

replace

If
a

pressure
drop
of
25

mmHg

0

98

inHg
is

exceeded
refer
to

the

following
chart
to
determine
the
cause

of

failure

Corrective
action

Replace
check
valve

Replace

Reinstall
and
check

push
rod

for

proper
turn

Replace

faulty
part
s

15
seconds

replace
check
valve
with
a

new
one

3
When

pressure
is

applied
to
the

Master
Vac
side
of
check

valve
and

valve
does
not

open
replace
check

valve
with
a

new
one

120
I

7IG

110
1
560

100

I
420

i
90
1
280

I

u

80
1
140

70
1
000

II

60
850

0

0

5

a
50
710

40
570

30
430

20
280

10
140

BR
15
1

I

Manifold

side

Master

Yac
side

1

Spring
2

Valve

BA289

Fig
BR

27
Sectional
view

of
check

valve

Operating
test

1
Connect

an
oil

pressure
gauge
in

brake
line

at
connection
on
master

cylinder

2
Install
a

spring
scale
on
brake

pedal

3

Start

engine
and
increase

engine

speed
until

a
vacuum

pressure
of
500

mmHg
19
69

inHg
is

registered
on

vacuum

pressure

gauge
With
a

vacuum

pressure
of
500

mmHg
19
69

inHg

held

measure
an
oil

pressure
with

respect
to

each

pedal

operating
force

Relationship
between
oil

pressure

and

pedal

operating
force
is
illustrated

in

Figure
BR
28
If

test
results
are
not

as

specified
in

Figure
BR
28
check

Master
Vac
for
condition
in

a
manner

as
described
under

Inspection
before

removal
of
this
unit

Also
check
brake
line
for
evidence

of
fluid

leakage

Note
Determine
whether
malfunc

tion
occurs
in
Master
Vac
or
in

check
valve

Always
inspect
check

valve
fiTlit

Condition

Excessive

pedal
travel

Spongy

pedal

Poor

braking
effect

Brakes

drag
Brake

Syst
em

TROUBLE
DIAGNOSES
AND
CORRECTIONS

Probable
cause

Low
brake
1uid
level
or

empty
master

cylinder
reservoir

Leakage
in
master

cylinder

Deteriorated
check
valve

Air
in

system

Faulty
brake

adjustment

Low

1uid
level
in
master

cylinder

Air
in

system

Faulty
brake

adjustment

Reservoir
filler

cap
vent

hole

clogged

Swollen
hose
due
to
deterioration

or
use
of

poor
quality
hose

Distorted

brake
shoes
or

excessively
worn

or

cracked

brake
drum

Soft
or
swollen

caliper
seals

Use
of
a
brake

1uid
with

too
low

boiling

point

Fluid

leakage
in

brake
lines

Low

brake
1uid
level

or

empty
master

cylinder
reservoir

Air
in

brake
lines

Excessive
shoe
ta
drum

clearance

Grease
oil

mud
or

water
on

linings
or

pads

Deterioration
of

linings
or

pads

Local
fit
of

linings
or

pads

Linings
or

pads
excessively
worn

Master

cylinder
or
wheel

cylinders
in

poor

condition

Binding
mechanical

linkage
at
brake

pedal

and
shoes

Clogged
brake
lines

Incorrect

adjustment
of

wheel

bearings

Improper
shoe
t

drum
clearance

Weak
shoe
return

springs

No
free
travel
in

brake
shoe

return

BR
22
Corrective
action

Fill
and
bleed
as

necessary
Test

for
source

of

leakage
by
examining
all
lines

connec

tions

and
wheel

cylinder

Overhaul
master

cylinder

Replace
check
valve
and
bleed

system

Bleed

system

Adjust
shoe
to
drum
clearance

Inspect

auto

adjuster
operation

Top
with
1uid
and

inspect
for

leakage

Correct
as

necessary

Adjust
shoe
to

drum
clearance

Inspect

aut

adjuster

operation

Clean
and

bleed

system

Replace
hose
and

bleed

system

Replace
faulty

parts

Drain

hydraulic
system
flush
with
alcohol

and

replace
all
seals

Replace
with

specified
brake

1uid
and
bleed

system

Check

master

cylinder

pIpIng
and
wheel

cylinder
for
leaks
and

repair

Fill
and
bleed

as

necessary

Bleed

system

Adjust

Clean
brake
mechanism
and
check
for

cause

of

problem

Replace
linings
or

pads

Replace

Shave
or

replace

Replace

Repair
or

replace

Free

up
as

required

Check
and

clean

Adjust
or

repair

Adjust

Replace

Adjust

pedal
height

Condition

Brake
chatters

Brake

squeals

Pedal

pulsates

Brakes
fade

Brakes

drag

Unbalanced
brakes
Brake

System

Probable
cause

Groove

or
out
of

round
brake
drum

Loose

or
bent

brake

disc

Distorted
brake
shoes

or

pads

Grease
or
brake
fluid
on

linings

Dirty
or
scored
brake

drums

Distorted
brake
shoes
or
bent

support
plate

Weak
or
broken
brake
shoe

retaining
spring

or

return

spring

Glazed
or
contaminated
brake

lining

Out
of

round
or
off
center
drum

Brake
fluid
has
too
low

boiling
point

Use
of

improper
linings
or
brake

linings
are

contaminated

Brake
drums
are
out
of
round

Hydraulic
connections
master

cylinder
and

wheel

cylinders
are

corroded
or

damaged

Bleed
screw
is

open

Pedal

linkage
is

binding
or

push
rod

adjust

ment
is
too

long

Master

cylinder
compensator
part
is
ob

structed

Seized
master

cylinder
piston

Poor
shoe
condition

Poor

wheel
cylinder
condition

Deformation
of

piston
cups

Hand
brake
will
not
return

Clogged
master

cylinder
return

port

Improper
tire
inflation

Improper
adjustment
of
shoe

to
drum
clear

anee

Grease
oil
mud
or
water
on

linings
or

pads

Mud
in

brake
drum

Deterioration
of

linings
or

pads

Excessive
wear
of

linings
or

pads

BR
23
Corrective
action

Grind
or

replace
as

required

Tighten

support
plate
bolts
to

specified

torque
or

replace
plate

Replace
as

necessary

Replace
linings

Blowout

assembly
with

compressed
air
or

refinish
drum

Replace
faulty
unit

Replace
if

faulty

Cam

ground
lining
to
eliminate

glaze
If

it

doesn
t

replace
linings

Turn

drum
or

replace
as
necessary

Drain
and
fill

system
with

approved
fluid

Replace
linings

Repair
or

replace
as
necessary

Repair
as
necessary

Close
screw
and
bleed

system

Lubricate

linkage
check

pedal
return

spring

for
condition
and

adjust
push
rod

as
neces

sary

Blowout

foreign
matter
with

compressed

air

Disassemble
master

cylinder
and

replace

piston
Bleed

system

Clean
and

repair

Repair
or

replace

Replace

Check
and

repair

Clean

Inflate
to
correct

pressure

Readjust

Clean
brake

mechanism
and
check
for
cause

of

problem
Replace
linings
or

pads

Clean

Replace

Replace

Condition

Pedal

yields
under

slight
pressure
Brake

System

Probable

cause

Wheel

cylinder
in

poor
condition

Poor

sliding
condition
of
brake
shoe

Looseness
of

cylinder
body
or

back

plate

securing
bolts

Scored
or
out

of
round
drums

Sticking
wheel

cylinder

cups

Deformation
of
back

plate

Incorrect

adjustment
of
wheel

bearings

Incorrect

adjustment
of
wheel

alignment

Looseness
of
leaf

spring
securing
U

bolts

Faulty
N
L

S
V

Deteriorated
check
valve

Ex

ternalleaks

Leakage
on
master

cylinder

BR
24
Corrective
action

Repair
or

replace

Adjust

Fasten
or

replace

Recondition
or

replace
brake

drum
as
reo

quired
Check
for

improper
lining
contact

with
drum
and

grind
lining
if

necessary

Recondition
or

replace
cylinder

Replace

Adjust
or

replace

Adjust

Tighten
or

replace

Replace

Replace
check
valve
and
bleed

system

Check
master

cylinder

piping
and

wheel

cylinder
for
leaks
and

repair

Overhaul
master

cylinder

DESCRIPTION

MAINTENANCE
AND
SERVICE

TIRE
INFLATION

TIRE
REPAIR

WHEEL
REPAIR

WEAR

DESCRIPTION

The

620
series
models
are

equipped

with

4lV
14

wheels
with
25

mOl
0
98

in

offset
All
tires

are
tubeless
Wheel

and
Tire

WHEEL
AND

TIRE

CONTENTS

WT2

WT
2

WT2

WT2

WT
2

WT
2
TIRE

ROTATION

CHANGING
TIRE

INSPECTION

WHEEL

BALANCE

WHEEL
AND

TIRE

Tire
size

Model
Tire
size
Wheel
size

All

models
6

00
I
4
6PR

Tubeless
4UJ
14

Tire

pressure

Unit

kgl
em
2

psi

Vehicle

speed
km
h

MPH
Under

Over

100
km
h
100
km
h

Model

60

MPH
60
MPH

Front

1
5
21
1
8

26

Unloaded

Rear
175

25
2
25
32

All

models

Front

1
5

21
1

8
26

Loaded

Rear
3
0

42
3
15
4S

Note
Tire
inflation

pressures
should

be
measured

when
tires
are
cold

MAINTENANCE
AND

SERVICE

TIRE

INFLATION

Correct
tire

pressure
is

very
im

portant
to
ease
of

steering
and

riding

comfort

This
also
reduces

driving

sound

to
a
minimum

resulting
in

longer
tire

life
that
is

overinflation
or
underinflation

promotes
wear
at

cen

ter
tread
or

shouider
of
tire

If

aU
tires
are

inspected
frequently

and
maintained

correct
tire

pressure
it

is

possible
to

detect

sharp
material

in

the
tread

Also
the
above
check

avoids

abnormal
wear
which
invites
serious

problem
If
tires
indicate

abnormal
or

uneven

wear
the
cause
of

problem

should
be
detected
and
eliminated

After

inflating
tires

leakage
in
valve

should
be

checked
Without

valve

caps

leakage
will

occur
due
to

dirt
and

water

resulting
in

underinflation
Ac

cordingly
whenever
tire

pressure
is

checked
be
sure
to

tighten
valve

caps

firmly
by
hand

WT
2
WT3

WT3

WTA

WTA

WT
4

TIRE
REPAIR

In
order

to

inspect
a
leak

apply

soapy
solution
to
tire
or

submerge
tire

and
wheei

in
the

water
after

inflating

tire
to

specified

pressure
Special
in

spection
for

leaks
should
be
carried

out
around
the
valve
wheel
rim
and

along
the
tread

Exercise
care
to
bead

and
rim
where

leakage
occurs

Wipe

out
water
from

area
which

leaks
air

bubbles
and

then
mark
the

place
with

chalk

After

removing
the
materials
which

caused

puncture
seal
the

point
When

repairing
the

puncture
use
the

tire

repair
kits

which
are
furnished
from

tire
dealers

following
the
instructions

provided
with
the

kits
In

case
that
a

puncture
becomes

large
or
there
is

any

other

damage
on
the

tire
fabric

repair

must
be

carried
out

by
authorized

tire

dealers

WHEEL
REPAIR

Inspect
the
wheel
rim

flange
for

bend

or
dents

The

flange
should
be
cleaned

by
a

wire

brush
when
rust
is
found

on
the

flange
Furthermore
if
excessive

pitting
occurs

on
the

rim
eliminate
it

with
a
file

WEAR

Missilgnment

When
the
front
wheels

align
in

excessive
toe
in
or

toe
out
condition

tires

scrape
the

tread
rubber
off
The

wear
of
tread

appears
feathered

edge

Center

This

wear
is
caused

by
overinflation

of
the
tire
The
inflation

pressure
must

be

kept
at
the

specified
value

Shoulder

The
wear

may
be
caused

by
under

inflation
incorrect
wheel
camber
or

continuous
high

speed
driving
on

curves
In

general
the
former
two

causes
are
common
Underinflation

wear
occurs
on

both
sides
of

treads

d
I

Ii

Toe
in
or

toe
out
wear

nf
I

Underinnation
wear

TIRE
ROTATION

Tires
wear

unevenly
and
become

unbalanced

according
to

running
dis

tance
Uneven
tire
wear
often
results

in
tire
noise

which
is
attributed
to
rear

axle

gears
bearing
etc
Meanwhile
the

front
tires
tend
to
wear

unevenly

because
of

improperly
aligned
front

wheel

Accordingly
to

equalize
tire
wear

it
is

necessary
to

rotate
tires

peri

odically

All
the
tires

including
the

spare
tire

are
of
the

same

type

Right
front

Right
rear

14
1

I

@
Spare

t
t
1

1

Left

front
Left
rear

Fig
WT
2
Tire
rotation
1
Wheel
and
Tire

and

on
the
other
hand
camber
causes

wear

only
on

one
side
of
treads
For

cornering
tread
wear
the

driver
must

operate
vehicle

slowing
down
on

curves

Uneven

Uneven
wear
is
caused

by
incorrect

camber
or
caster

malfunctioning
sus

pension
unbalanced
wheel
out
of

round

brake
drum
or
other
mechani

cal
conditions
To

repair
this
abnormal

wear

correct
the

above

faulty
parts

J

I

II

i

11
I

1

Overinllation
wear

1

I
I

t

Uneven
wear
WT007

Fig
WT
1
A
bnormal
tire
wear

The

spare
lire
has

a
different
brand

from
4
tires
on

the
vehicle

Right
front

Right
rear

I

@
Spare

x

J
r

Left
front
Left
rear

The

pare
tire
should
be
used

in
an

emergency
only

Fig
WT
3
Tire
rotation
2

The
tires
are

provided
with
tread

wear

indicator
at
six

places
around

tire
circumference
indicating
1

6
mm

J
in
tread

depth
When
the
tires

wear
and
then
the
marks

appear
re

place
them
with

new
ones
See

Figure

WT

4

WT3
Tire
tread

0E
I
Tread

wear
indicator

c

WH024

Fig
WT
4
Tread
wear
indicator

CHANGING
TIRE

To

change
tire
with
wheel

using
a

jack
in
the
safe
manner
observe
the

following
procedures

1
To

remove

spare
tire
insert

jack

rod

to

guide
and
then
turn
it
counter

clockwise
When

installing
lighten
a

little

strong
after

lifting
up
and
lock

Fig
WT
5
Removing
spare
tire

2
It
is

necessary
to
remove
wheel

cap
and
temporarily
to
loosen

wheel

nuts
before
vehicle
is

jacked
up

3
To

jack
up
front

place

jack
under

side

frame
about
S20

mOl
20
5
in
at

rear
of
front
axle

center
after

apply

ing
parking
brake
and

blocking
rear

wheels

g
1

WT012

Fig
WT
6

Jacking
up
front
side

4
To

jack
up
rear

place
jack
under

rear

axle
case
close
to
the
side

of
rear

spring
after

applying
parking
brake

and

blocking
front
wheels

WH077

Fig
WT
7

Jacking

up
rear
side

S

Remove
wheel
nuts
and
wheel

from
drum

6
To

install
wheel

reverse
the

above

steps

Tighten
wheel
nuts
in
criss
cross

fashion
to
8

0
to
9
0

kg
m

S8
to
6S

ft

Ib

Note
Nerer

get
under
the
vehicle

while
it

is

supported
only
by
the

jack
Always
use
S8

fety
stands
to

support
the

side
member
of

body

construction
when

you
must

get

beneath
the
vehicle

INSPECTION

WHEEL
BALANCE

The

wheel
arid
tire

asSembly
should

be

kept
balanced

statically
and

dynam

ically
Wheel
and
Tire

Proper
tire

balance
is

necessary

when

driving
the
vehicle

at

high

speeds

Consequently
the

wheel
and

tire

assembly
should
be

properly
re

balanced
whenever

puncture
is

re

paired

The
wheel
and

tire

assembly
be

comes
out
of
ba1ance

according
to

uneven
tire
wear

Severe
acceleration

and

braking
or
fast

cornering
is
the

cause
of

wear

on
tire

resulting
in

unbalance
of
tire
and
wheel

assembly

The

symptom
of
unbalance

appears

as

tramp
vehicle
shake
and

steering

malfunction

To

correct
unbalance

use

proper

wheel
balancer

Maximum

allowable

unbalance

177

gr
cm
2
5
in

oz

10

gr
O
3S
oz
at
rim

circumferences

Balance

weight

10
to
60

gr
O
3S

to
2
12

oz

at

10

gr
0
3S

oz
intervat

Note
Be

sure
to

place
the
correct

balance

weights
on
the

inner

edge

of
rim
as

shown
in

Figure
WT
S

00
not

put
more
than
two

weights

on
each

side

WHEEL
AND
TIRE

In

order
to
ensure

satisfactory

steering
condition
as

well

as
maximum

tire
life

proceed
as
follows

Check

wheel
rim

for
rust

distor

tion
cracks

or
other
faults

WT
4
Thoroughly
remove
rust
dust

oxidized
rubber

or
sand
from
wheel

rim
with
wire

brush

emery
cloth

or

paper
Use

dial

gauge
to
examine

wheel
rim

for
lateral

run
out

Lateral
run
Qut
limit

Less

tltan
1
5
mOl
0

059

il
total

indicator

reading

WTOO5

Fig
WT

B
Whetl

rim
run

out
check

points

Note
In

replacing
tire

t
e

extra
care

not
to

damage
tire
bead

rim

flange

and
bead
seat

Do

not

use
tire
irons

to
force

beads

away
from

wheel
rim

flange
that
is

always
use
tire

replacement
device

whenever

tire
is
removed

2

Discard
when

any
of

the
follow

ing
problems
occur

1

Broken
or

damaged
bead
wire

2

Ply
o

treairsepanitiori

3

Cracked
or

damaged
side

wall

etc

Condition

Wheel
wobbles

Unevenly
or

excessively
worn

tire

Tire

squeals
Wheel
and
Tire

TROUBLE
DIAGNOSES
AND
CORRECTIONS

Probable

cause

Improper
tire

pressure

Damaged
tire

or
distorted
wheel

rim

Unbalanced
wheel

Loose
wheel
nuts

Worn
or

damaged
wheel

bearing
or
excessive

play
of
wheel

bearing

Improper
front
wheel

alignment

Worn

or
damaged
ball

joint

Excessive

steering
linkage

play
or
worn

steering

linkage

Loose

steering
linkage
connection

Broken

suspension
spring

Damaged
shock

absorber

Improper
tire

rotation

Improper
tire

pressure

Unbalanced
wheel

Improperly
adjusted
brake

Improper
wheel

alignment

Excessively
distorted
or

improperly
installed

suspension
link

High
speed
on

curves

Sudden
start

and

improper
speed
due
to

rapid
acceleration

or

improper
brake

ap

plication

Improper
tire

pressure

Improper
front
wheel

alignment

Distorted
knuckle
or

suspension
link

WT
5
Corrective
action

Measure
and

adjust

Repair
or

replace

Balance

Tighten

Correct

play
or

replace
wheel

bearing

Align

Replace

Adjust
Or

replace

Tighten
nuts
to
rated

torque
or

replace

worn

parts
if

any

Replace

Replace

Conduct
tire

rotation

periodically

Measure
and

adjust

Balance

or

replace

Adjust

Align

Repair

replace
or
if

necessary
reinstall

Reduce

speed

Follow
correct
and

proper
driving
manner

Measure
and

adjust

Align

Repair
or

replace

STEERING
SYSTEM

TROUBLE
DIAGNOSES
AND
CORRECTIONS

Condition

Steering
wheel
moves

heavily

Steering
wheel
turns

but

sluggishly

Vehicle

pulls
to
one

side
Probable
cause

Wheel

alignment
out
of

specifications
or
air

pressure
in
tires

too
low

Steering

linkage
out
of

adjustment

Steering
column
out
of

alignment

Wheels
out
of

alignment
or
air

pressure
in

tires

too
low

Damaged
steering
linkage

Wheels
out

of

proper
alignment

Wheel

bearing
out
of

adjustment

Damaged

steering
linkage

ST
9
Corrective
action

Align
or

inflate
tires

to
correct

pressure

Adjust
and

see
relative

topic
under
Front

Suspension

Repair

Repair
or
inflate
tires

to
correct
air

pressure

Replace
and
see
relative

topic
under
Front

Suspension

Align

Adjust

Replace
and

see
relative

topic
under
Front

Suspension

DESCRIPTION

REMOVAL

DESCRIPTION

The
fuel
tank
is4Sliters
II

Ji
U
s

gal
9
Ji

Imper
gal
in

capacity
The

tank
unit
is

mounted
to

the

right
side

of
the
rear

floor

1
Fuel

tank

2
Drain

plug

3
Filler
tube

4

RescfYOir
tank

5
Filler
hose

6
Breather
hose

7
Ventilation
hose

8

Evaporation
hose

9
Fuel
outlet
hose
and
tube

10
Fuel

tank

gauge
unit

11

Protector

12
Bracket

13
Retainer

14
Return

tube
Engine
Control
Fuel
Exhaust

Systems

FUEL
SYSTEM

CONTENTS

FE
4

FE
5
INSPECTION

INSTALLATION
FE
6

FE
6

The
filler
shutter
is
installed
to

the

filler
tube
on
California
models

The
electric
fuel

pump
is

adopted

on
air

conditioner

equipped
models
For

the
electric
fuel

pump
refer
to

Section
EF

FE194

Fig
FE
3
Fuel
tank

FE
4