Cooling System; Fan Belt Tension; Flushing And Draining The System; Water Pump Replacement/Thermostat Testing - Datsun 510 series Workshop Manual

CoolIng System
GENERAL
FAN BELT TENSION
FLUSHING AND DRAINING THE SYSTEM
THERMOSTAT Testing
RADlA TOR Removal
GENERAL
The cooling system
is pressurised
and
incorporates
a
water
pump
corrugated
fin type radiator fan and
a
pellet
type
thermostat
The
water pump
is of the
centrifugal
type and has an
aluminium die cast
body The volute chamber is built
into
the
front
cover
assembly
and
a
high
pressure
sealing
mechanism
prevents
water
leakage
and noise
The fan pulley
is driven
by
the
V belt from
a
pulley
on
the crankshaft
he
pellct
type thermostat enables the
engine to
warm up
rapidlY and also regulates
the
temperature
of the coolant When
the
wax
pellet in the thermostat is heated it expands and
exerts
pressure
against
a
rubber diaphragm causing the valve
to
open
and allow the coolant to
flow from the cylinder head back
to
the radiator
As the pellet
is
cooled itcontractsand
allows
the
spring
to
close the valve thereby preventing coolant from leaving the
cylinder head
The rad
ator
is of the down flow type with
an expansion
tank The relIef valve in the radiator filler cap controls the
pressure at
approximately 0
9
kg
sq cm
l3Ib sq in Always
try to
avoid
removing
the filler
cap
when the engine is hot
as
coolant
may spray out
and
cause
scalding
If the cap
must
be removed in these circumstances
use a
lar
e
pic
c
of cloth
to
hold the
cap
and
turn
the
cap
sli htlY
Walt until all pressure has been released before lifting off the
cap
FAN BELT TENSION
The fan belt drives the
water
pump and alternator
as
well
as
the fan and its
correct
adjustment is
most
essential A loose
fan belt will sl ip and
Y
e r
and
most
probably
cause
overheating
alternatively
If the belt
IS
too
tight
the
pump
and alternator
bearings
will be overloaded
The belt
is
correctly tensioned if it
can
be
depressed by
approximately 10
mm
1 2 in
at
a
point midway between the
fan and alternator
pulleys See
Fig R2
If
adjustment
is
neces ary
slacken the alternator
mounting
and
adjustment
bolts and pivot the alternator
away
from the
engine
to
tighten the belt
to
towards the engine
if the belt is
to
be slackened
NOTE Always apply leverage to
the drive end
housing
when
pivoting
the alternator and
never
to
the diode end
housing
or
the alternator will be damaged
Retighten
the alternator bolts and make
SUfe
that the belt
is
correctly
tensioned
FLUSHING AND DRAINING THE SYSTEM
The radiator and water
passages
should
be flushed out
periodically
to
remove
the
accumulated scale
or
sediment
Reverse flushing equipment
should be used to carry out
a
completely thorough flushing operation
but the
owner
drivef
not
possessing this type
of equipment
can
flush
out
the
system
in the
following
manner
Drain the system
by removing
the radiator filler
cap
and
opening the radiator and cylinder
block drain taps Close the
taps
again
and refill the radiator
Run
the
engine
for
a
ShOft
period
and then
rc open
the drain taps Continue this sequence
until the
water
flowing
from the
taps
is clean then close
the
taps
and refill the radiator
An anti freeze mixture should
always
be used in Winter
time The Niss3n long
life coolant L L c is
an
ethylene glycol
solution containing a
corrosion preventative
which
can
remain
in the vehicle throughout the
year
but
must not
be mixed with
other
products
It is advisable
to
check the radiator and heater hoses when
filling with anti freeze and
renew
them if
signs
of deterioration
are
apparent
WATER PUMP
Replacement
The water pump must not
be dismantled and should be
renewed if
it
becomes
faulty
The pump
can
be removed in the
following
manner
Drain the cooling system
2
Take the fan belt off the
pulley
3
Remove the fan and pulley
4 Remove the
retaining
nuts
and withdraw the water
pump
See Fig B 3
lnstallation of the pump is
a
reversal of the removal
procedures
rERMOST
ATTesting
The thermostat is located in the
water
outlet passage
See
Fig
B 4
To
remove
the unit drain the
cooling system
remove
the radiator hose and the water
outlet elbow Take out
the thermostat
25