1973 DATSUN B110 low oil pressure

Pedal

yields
under

slight

pressure

Excessive

pedal

travel

All

brakes

drag

One
brake

drags

Unbalanced
brakes
BRAKE

Use
of
a
brake
fluid
with

a

boiling
point

which
is
too
low

Reservoir

filler

cap
ven
t
hole

clogged
This

promotes
a
vacuum
in
master

cylinder
that

sucks
in
air

through
rear
seal

Deteriorated
check
valve

External

leaks

Master

cylinder
leaks

through
primary
cap

System
has

not
been
bled

Improperly
adjusted
clearance

Fluid
level
in

master

cylinder
is
too
low

Thermal

expansion
of
drums
due
to

over

heating

Insufficient
shoe
tlrdrum

clearance

Weak
shoe

return

springs

Brake
shoe

return
no
free

travel

Seized
master

cylinder
piston

Loose
or

damaged
wheel

bearings

Weak
broken
or

unhooked
brake

shoe

return

springs

Insufficient
clearance
between
brake
shoe

and
drum

Grease
or
oil
on

linings

Seized

piston
in
wheel

cylinder

Tires

improperly
inflated

Loose
wheel

bearing

BR
25
Change
with
the

specified
brake

fluid
and

bleed

system

Clean
reservoir
filler

cap
and
bleed
the

system

Fit
a

new
check

valve
and
bleed
the

system

Check
master

cylinder
piping
and

wheel

cylinder
for
leaks
and
make

necessary
re

pairs

Overhaul
master

cylinder

Bleed

the

system

Adjust
shoe

to
drum

clearance

Full

up
with

specified
brake

fluid

Bleed
the

system
if

required

Allow
drums

to
cool
off
Check
brake

shoe

linings
and
drums

Replace
damaged

parts

Adjust
clearance

Replace
the

springs

Adjust
pedal
height

Service
the

master

cylinder
replace
the

piston
and
bleed

the

system

Adjust
or

replace
wheel

bearings

Replace
spring

Adjust
brakes

Clean
brake
mechanism

replace
lining
and

correct
cause
of

grease
or

oil

getting
on

lining

Service
the
wheel

cylinder
and

bleed
the

system

Inflate
tires

to
correct

pressure

Adjust
wheel

bearing

BODY

REGULATOR

FUSE
M

TEMPE

RATURE

GAUGE
IGNITION

SWITCH

Lf

I

iT
Ji
1M

THERMAL
TRANSMITTER
I

J

0

I
GAUGE
TANK
UNIT

FUEL
TANK

Fig
BE
38
Circuit

diagram
for
fuel
gauge
temperature
gauge
and

voltage

regulator

Replacement

Remove
the

cluster
lid
first

2
Unscrew
two

screws
and
remove
the

thermometer
or

fuel
meter

from
the

combination
meter

housing

3
Reinstall
a
new
meter
in

reverse

sequence
of
removal

Fig
BE
39

Removing
thermometer

OIL
PRESSURE
AND

IGNITION
WARNING
LAMPS

The

engine
lubricating

system
incorporates
an
oil
pressure

warning
lamp
which

glows
whenever

engine
oil

pressure
falls
below
0
4

kg
ern
to
0
6

kg
em
5
7
to
8
5

lb

sq
in

When
the

engine
is

stationary
the

light
glows
with
the

ignition
switch
turned
on
When
the

engine
is

running
and

the
oil

pressure
reaches
the

circuit
is
broken
and
the

light

goes
out

J

u

fj
Warning
lig

2
Fuse

bSM
Q

f

t

J

without

pressu
re
with

pressure

Fig
BE
40
Circuit

of
oil

pressure
warning
system

Ignition
warning
lamp
glows
when
the

ignition
switch

is
set
to
ON
and
the

engine
is
not

operated
or
when
the

generator
fails
to

charge
with
the

engine
operated

BE
20

BODY
ElECTRICAL

When
the

ignition
switch
is
set
to
ON
the

ignition

wa

rning
circuit
is

closed
and
current
flows
flows
from
the

ignition
switch
to
the

warning
lamp
bulb

and

ground

through
the

regulator
When
the

engine
is
started
and
the

generator
comes
into
operation
the

generator
output

current

opposes
the
current
flowing
from
the

warning

lamp
in

effect
it
breaks
the

warning
circuit

ground

connection
and
the

lamp
goes
out

l

r

hffi
u

z
Ignition
switch

I
Q
6

I
0

c

M
1
E

8

ca
i

L

g

PI
lot
c

P

I

j

co

rt
0

relay
E
0

5

y
y
1

N
N
3

Alternator

Regulator

Fig
BE

41
Circuit

of
ignition
warning
system

HAND
BRAKE
WARNING
LAMP

This

lamp
functions
both
hand
brake

warning
larnp
and

BULB
SPECIFICATIONS
service
brake
line

pressure
differential
warning
lamp

When
a

difference
between
front
and

rear
brake
line

pressures
reaches
the
rated

range
13
to
17

kgfcm2
185

to

242
lb

sq
in
the

ground
circuit
for
the

warning
lamp

is

closed
and
the

warning
lamp
lights

IGNITION
SWITCH

WARNING

LAMP

L
E

WARNING

SWITCH

1
SERVICE

BRAKE
LINE

PRESSU
R
E

DIFFERENTIAL

WARNING

J
SWITCH

Fig
BE

42
Circuit

diagram
for
brake

warning

system

tern
Specifications

Square

type
meter
Round

type
meter

Meter
illumination

larnp
VoW
12
3
4
2
12

1
7
3

Turn

signal
pilot
lamp
VoW
12
3
4
2
12
1
7
2

Head

lamp
main
high
beam

VoW
12
3
4

I
12

17
1

pilot
lamp

Ignition
warning
lamp
VoW
123
4

I
12
17
1

Oil

pressure
warning
lamp
VoW
12
3
4

1
12
1
7

1

Hand
brake

warning
lamp
VoW
12
1
7
1

for
U
S
A

CANADA

Clock
illumination

lamp
VoW
123
4
I
12
17
2

Figure
encircled
in

parentheses
indicates
number
of
bulbs
used

BE
21

BODY
ELECTRICAL

Improper
cable
contact

Oil

pressure
and

ignition
warning
lamps

Condition

Oil

pressure
Want

ing
lamp

The

lamp
does
not

ligh
t
when
the

ignition
switch
is

set

to
ON
Probable

cause

Blown
off

fuse
or

faulty
contact

Broken

lamp
bulb
fIlarnent
or

faulty
cable
contact

Defective
oil

pressure
switch

The

lamp
does
not
Oil

pressure
is

too
low

go
out
while
the

engine
is

being

operated
Lack
of

engine
oil

Defective
oil

pressure
switch

Ignition
warning

lamp

The

lamp
does

not

light
when

the

ignition

switch
is
set
to

ON
Blown
off
fuse
or

faulty
contact

Burnt
out

light
bulb
filarnent
or

faulty
cable
contact
The
fuel
rneter
indicates
a

level

slightly
lower
than

the
actual

level

Method
of

inspection

Check
the

fuse
for

fusing
and

faulty
contact

The

warning
lamp
does
not

light

when
oil

pressure
switch

yellow

black
cable
is

grounded

The

warning
lamp
lights
through

the

above

inspection

Inspect
the

engine
oil

pressure

system

Check
oil
level

Continuity
exists
on
the
oil

pres

sure
switch
when
the

engine
is

being
operated

Check
the
fuse
for

fusing
and

faulty
contact

The

pilot

lamp
does
not

light

when
the

voltage
regulator
con

nector
is
disconnected
the

white
red
cable
is

grounded
and

the

ignition
switch
is
set
to
ON

BE
25
Check
the
cable

from

the

fuel
meter
to
the

tank
unit
for

cable

being
about
to
break

poor
contact
and

faulty
grounding
and

repair
as
required

Corrective

action

Replace
after
corree

ting
the

fuse
the

cause
if
fused

Check
the

light
bulb

for
burnt
out
fIla

ment
and

replace
as

required

Replace
the
oil

pres

sure
switch

Add
oil

Replace
the
oil

pres

sure
switch

Repair
or

replace
as

required

Check
the
bulb
for

burnt
out
fIlament

and

replace
as
re

quired

ENGINE

operating
mechanism

Adjust
valve

clearance
at

following
four

points
while

engine
is
still

hot

G
Exhaust

valve
of
No
1

cylinder

CV
Intake
valve

of
No
1

cylinder

CID
Intake
valve

of
No
2

cylinder

CID
Exhaust
valve
of
No
3

cylinder

Note
Numbers
in

parenthesis
agree
with
those
in

ac

companying
sketch

I

Fig
BY

1

Adjusting
valve
clearance

4

Again
rotate

crankshaft
one
turn
so
that
No
4

piston

is
in

top
dead
ce
lter
on
its

compression
stroke

Adjust

follnwing
valves

@
Exhaust
valve
of
No
2

cylinder

@
Intake

valve
of
No
3

cylinder

f
Intake
valve

of
No
4

cylinder

@
Exhaust
valve

of
No
4

cylinder

Adjustment
should
be

made
while

engine
is
hot
After

all

valves
have

been

adjusted
correctly
tighten
lock
nut

firmly
to

secure
the

adjustment

Vah
e
clearance

Hot
Intake

0
35

mm
0
014
in

Exhaust
Checking
and

adjusting
drive

belt

II

I

Fig
ET
2

Adjusting
drive
belt

tension

I

Check
for
a

cracked
or

damaged
V

belt

Replace
if

defective

2

Adjust
the
belt
tension
if

necessary

Belt
deflection
when

thumb

pressure
of
10

kg
22
0
lb

is

applied
midway
between

pulleys
10
to
15
mm

0
394

to
0
590
in

Retightening
cylinder
head
bolts

manifold
nuts

and
carburetor

securing

nuts

Cylinder
head
bolts

When
the

engine
is
in

cold

tightening
should
be
made

in

several

steps
and
in

sequence
shown
in

Figure
EM
82

page
EM
31

starting
with
the
center

toward
the

ends

Tightening
torque

1st
turn

2nd
turn
4

0
to
4
5

kg
m
29
to
33

ft
lb

5
5

to
6
0

kg
m

40
to
43
ft
lb

Then
warm

up
the

engine
and

retighten
the
bolts
to
the

specification
of
hot
condition

Tightening
torque
hot

6
0

to
6
5

kg
m
43

to
47
ft
lb

Other

tightening
torque

Manifold
nuts
0
9
to
14

kg
m
6
5
to
10
ft
lb

Carburetor
nuts
0
5

to
LO

kg
m
3

6
to
7
2
ft
lb

Checking
engine
oil

Oil

capacity
of

engine
including
oil
filter

ET
2

EMISSION
CONTROL
AND

TUNE
UP

Capacity

Maximum
3
3
L
X

US

gal
y

Imp
gal

2
3
L
US

gal
f

Imp
gal
Minimum

Make
sure
that

engine
oil
is

not
deteriorated
with

cooling
water
or

gasoline
Drain

and
refill
the
oil

if

necessary

Notes

a
A

milky
oil
indicates
the

presence
of

cooling

water

Find
the
cause
for

necessary
corrective
action

b
Oil
with

extremely
low

viscosity
indicates

dilution
with

gasoline

2
Check

oil
level
If
found
below
L

mark
refill
to

H
mark

on

gauge

Fig
ET
3

Checking

engine
oil
level

Replacing
oil
filter

The
oil
ftIter
is
of
a

cartridge
type
The
oil
filter

can
be

removed

using
oil
ftIter
wrench
STl9320000
Check
for
oil
leaks

through
gasketed

flange
If

any

leakage
is
found

retighten
slightly
If

necessary

replace

filter
as
an

assembly

2
When

installing
an
oil
filter

tighten

by
hand

Note
Do
not

overtighten
oil
filter
or
oil

leakage
way

result

Changing
engine
coolant
L

L
C

Nissan

long
life
coolant

LLC
is
an

ethylene
glycol
base

product

containing

chemical
inhibitors
to

protect
the

cooling
system
from

rusting
and
corrosion

The
L
L
C

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

temperature
thermostat
It

flows

freely
transfers
heat

efficiently
and
will
not

clog
the

passages
in
the

cooling

system
The
LL

C
must
not
be

mixed
with
other

products
This
coolant
can
be
used

throughout
tlie

seasons
of
the

year

Whenever

any
coolant
is

changed
the

cooling
system

should
be
flushed
and

refilled
with
a
new

coolant

Check
the
level
J

Percent
Boiling
point

0
9

kgfcm2
Freeze

concen

tration
Sea
level

cooling
sys
protection

tern

pressure

30
1060

C
I

240C
15OC

221OF
255OF
5OF

50
IUY
C
1270C
35
C

2280
F
2610F
3IOF

DC
OF

0

321

10
14

20141

50
58
I

I

I

I

1

I

I

1
30
1
22

40

401

40
10
30
50
20

EGOOl

Fig
ET
4
Protection

concentration

ET
3

ENGINE

Checking

cooling
system
hoses

and
connections

Check

cooling
system
hoses

and

fiHings
for
loose

connections
and
deterioration

Retighten
or

replace
as

necessary

Inspection
of
radiator

cap

Apply
reference

pressure
0
9

kg
cm1
13

psi
to

radiator

cap
by
means
of
a

cap
tester
to

see
if
it
is
in

good
condition

Replace
cap
assembly
if

necessary

ET012

Fig
ET
5

Testing
radiator

cap

Cooling
system

pressure
test

With
radiator

cap
removed

apply
reference

pressure

1
6

kg
cm1
23

psi
to
the

cooling

system
bv
means

of
a

tester
to
check

for
leaks

at
the

system
compo

nents

Water

capacity

with
heater

4
9
l
I
Y
US

gal
l
i

Imp
gal

without
heater
4
2

l

I
i
US

gal
i

Imp
gal

Fig
ET
6

Testing
cooling
system
pressure
Checking
vaccum

fittings
hoses

and
connections

Check
vacuum

system
fittings
and
hoses
for

loose

connections
and

deterioration

Retighten
if

necessary

replace
any
deteriorated

parts

Checking

engine
compression

Compression
pressure
test

Note
To
test

cylinder

compression
remove
all

spark

plugs
and
hold
tester

fitting
tightly
in

spark
plug

hole
of

cylinder

The

tester
is
used
to

determine
whether

cylinder

can
hold

compression
or
whether
there
is

excessive

leakage

past
rings
etc

I

Td10

l
y

Fig
ET

7

Testing

compression
pressure

Test

compression
with

engine
warm
all

spark
plugs

removed
and
throttle
and
choke
valve

opened
No

cylinder

compression
should
be
less

than
80

of

highest
cylinder
s
Excessive
variation

between

cyl

inders

accompanied
by
low

speed
missing
of
the

cylinder
usually
indicates
a

valve
not

properly
seating

or
a
broken

piston
ring
Low

pressures
even

though

uniform

may
indicate
worn

rings
This

may
be

accompanied
by
excessive

oil

consumption

Test

conclusion

If
one
or
more

cylinders
read
low

inject
about
one

tablespoon
of

enigne
oil
on

top
of
the

pistons
in
low

ET
4

EMISSION
CONTROL
AND

TUNE
UP

reading
cylinders
through
spark
plug
hole

Repeat

compression
check
on
these

cylinders

1

If

compression
improves
considerably

piston
rings

are
defective

2
If

compression
does
not

improve
valves
are

sticking

or

seating
improperly

3
If
two

adjacent
cylinders
indicate
low

compression

and

injecting
oil
on

pistons
does
not
increase

compres

sion
the

cause

may
be
a

cylinder
head

gasket
leak

between
the

cylinders
Engine
oil
and
coolant

in

cylinder
could
result
from
this

problem

Compression
pressure

12
S
to
14
S

kg
cm2

178
to

206

psi
at
3S0

rpm

Checking
exhaust
manifold
heat

control

valve

Check
heat

control
valve
for

proper
operation
If
it

does
not

operate
properly
trouble
is
due
to

excess
carbon

on
shaft
or

damaged
shaft
Clean
if

necessary
The
bimetal

should
be
also
checked
for

proper
function

IGNITION

AND

FUEL
SYSTEM

Checking

battery

Check

electrolyte
level
in
each

battery
celL

L

Unscrew
each

filler

cap
and

inspect
fluid
leveL
If

fluid

level
is

low
add

distilled
water
to

bring
level

up
to

app
roximately
10
to
20

mm
0

3937
to
0
7874
in
above

plates
Do
not
overfilL

2
Measure

specific
gravity
of

battery
electrolyte
ET002

Fig
ET
B

Checking
the

specific
gravity
of

battery
electrolyte

Permissible
Full

charge
value

value

at
200C
68OF

Frigid
climates
Over
1
22
1
28

Tropical
climates
Over
1
18
1
23

Other
climates
Over
L
20
1
26

Clean
the

top
of

battery
and
terminals
with
a
solu
lion

of

baking
soda

and
water
Rinse
off
and

dry
with

compressed
air

The

top
of

battery
must
be
clean
to

prevent
current

leakage
between
terminals
and
from

positive
terminal
to

hold
down

clamp

In
addition
to
current

leakage
prolonged
accumulation

of

acid
and
dirt
on
the

top
of

battery
may
cause

blistering

of

the
material

covering
connector

straps
and
corrosion

of

straps
After

tightening
terminals
coat
them
with

petro

laturn

vaseline
to

protect
them
from
corrosion

Checking
and

adjusting
ignition

timing

I

Check

spark

plugs
and
distributor
breaker

points
for

condition

2

Thoroughly
wipe
off
dirt

and
dust
from

timing
marks

on
crank

pulley
and
front

cover

3
Warm

up
engine
sufficiently

ET
5