PEUGEOT 404 - Routine Maintenance, Fan Belt Tension; The Cooling System

CHAPTER 4
THE COOLING SYSTEM
4:1
Description
4:2 Routine maintenance, fan belt tension
4:3 Removing
and
installing
the
pump
4:4
Pump dismantling and testing
4:1 Description
The cooling
system incorporates
a radiator,
a centri-
Íugal
pump,
a thermoswitch
and a magnetic type Ían
to
keep the
engine
at
its most
efÍicient
temperature.
On
later
models the
system is
pressurized
to 4
lb/sq inch
by
the Íitting
of a
pressure/vacuum
cap
which allows
a
water
temperature
of
107"C (225"F)
before boilrng.
In
the magnetic
clutch
fan
(see
FIG
4:1),
the
electro
magnet
A, is integral
wilh the
water
pump pulley.
The
fan
is loose
on the water
pump
shaft
and is connected
with the
armature B, through
three
elastic bars
C, which
provide
the
drive when the
armature
is attracted
by the
magnet.
The
electric
current which
actuates the magnet
is fed
through
a thermo-swttch
control
screwed into
either tne
cylinder head
or the radiator.
When the
cooling water temperature
rises to
approxi-
mately 185"F,
the thermo-control
switches
on and the
fan takes
uD the.
drive.
When
the
cooling water
temperature
drops,
the
thermo-control switches ofÍ at a much lower
temperature
and disengages the fan. The
18oF
interval
between
on
and
off temperatures
represent
a sufficient time
period
to
avoid
too
frequent
switching
on and oÍf
.
P404
4:5 Pump reassembly
4 :6 Testing
the thermo-switch
and thermostat
4:7 Fault
diagnosis
The
electric current from
the thermo-control
D,
reaches
a carbon
E, mounted
on the water
pump
body,
which
bears on the insulated
collector ring F,
which, in
turn,
is connected to
one end of the wire
oÍ the electro-
magnet coil G, the
other end
of which is earthed to
the
revolving
mass. The curient
returns from the
revolving
earth to
a solid earth through
the
water
pump
shaÍt,
impeller
and axially
through
the
carbon oÍ the
seal
to
the
water
pump
body.
4
:2
Routine
maintenance, fan belt
tension
There is only one
lubrication
point
and
this is
a nipple
on
the water
pump
casing which should
be
oiled
with
engine oil at
every
1800 miles.
The cooling system should
be drained,
Ílushed
through and reÍilled at
regular intervals.
During very cold weather, anti-freeze
should be
added
to the
cooling
system to
prevent
Íreezing. Before
adding
the anti-freeze
mixture, the cooling system
should be drained
and
Ílushed through with water until
it runs
out
clean. Before
refilling, check the condition
of all hoses and connections
in the cooling system and
to the heater. Inspect
the cylinder head to block and other
37