Operation Manual

Thermometer
Neither must touch the walls
or base of the container
Thermoswitch
Thermometer
Thermostat must be
totally
submerged
Neither must touch the walls
or base of the container
- Remove the bleed screw from the
water pump cover and do not reins-
tall it until the coolant fluid flows out
with no bubbles.
- Close the plug-valve of the expan-
sion vessel. Heat up the engine until
the thermostat opens.
- Check that the radiator body warms
up; if it fails to warm up this indica-
tes that the thermostat has failed to
open, or that there are air bubbles
inside the coolant liquid circuit.
- Stop the engine and allow to cool.
- Refill the expansion reservoir with
coolant liquid until the minimum
level in the reservoir is reached
(when the engine heats up the level
will rise owing to the expansion of
the liquid in the circuit.
- Check the electric circuit of the
overheating warning lamp on the
instrument panel by disconnecting
the temperature sensor connector
spade and connecting the terminal
to earth via a short length of cable,
then operate the contact and the
warning light on the instrument
panel should light up.
- In order to check the cylinder head
temperature sensor, as well as the
electric fan operating thermos-
switch (only in versions fitted with
this equipment) submerge the ope-
rative part of these components in a
container of water (without it tou-
ching the sides of the container)
and heat up the water. Connect an
ohmmeter between the metal body
of the devices and the connector
terminal, and check that as the tem-
perature of the water rises, the
resistance reading at the sensor
falls; if this is not the case, replace
the thermo-switch.
- The thermostat should be checked by submerging it
in a container of water (without touching the sides or
bottom) and heating the water. Using a thermometer
note the temperature when the contact starts to
open and again when it stops opening (fully open
position).
6-3
Inspection of the thermoswitch
Measurement temperature valve opening
Sensor ON OFF
Cylinder head
cooloant
124 ± 3ºC 114 ± 3ºC
temperature
Electric fan
thermo-swich
97 ± 3ºC 85 ± 3ºC
Temperature ºC 67±3ºC 75ºC
Thermostat opening
(mm.)
0,1 3,0