Checking and topping up fluids
►
Please read the information on ðpage 240,
Cooling system before topping up the coolant
in the coolant expansion tank.
Wait until you can no longer see or hear es-
caping steam or coolant.
– When working in the engine compartment
be aware that the radiator fan may start
running suddenly, even if the ignition is
switched off – risk of injury!
Topping up the coolant
Important: A visible amount of coolant must re-
main in the coolant expansion tank ð
.
– The coolant and coolant additives can be a
health hazard. Store the coolant additive in
the original container in a safe place out of
reach of children – risk of poisoning.
If you do need to top up the coolant, use a mix-
ture of distilled water and the specified coolant
additive. Only use non-distilled water in an emer-
gency. Always use clean water.
CAUTION
Applies to vehicles with mild hybrid technology:
The caps for the two coolant expansion tanks
Coolant loss which leads to the coolant ex-
pansion tank being empty normally indicates
significant leaks in the cooling system which
could result in further damage. In this case,
do NOT drive on. Seek professional assistance.
– Do not add coolant if the expansion tank is
empty. Air could have got into the cooling
system – risk of damage! In this case, do
NOT drive on. Seek professional assistance.
– If there is a visible amount of coolant re-
maining in the tank, add more coolant.
must not be swapped over ð
.
Coolant circuit for combustion engine: black cap
ðFig. 124
Applies to vehicles with mild hybrid technology:
Coolant circuit for electrical components: blue
cap ðFig. 125
►
Wait for the engine to cool down.
►
Cover the cap on the expansion tank you intend
to open with a large, thick cloth.
Drive to a qualified workshop without delay
and have the fault rectified. If the warning/
►
Carefully unscrew the cap for the affected cool-
ant circuit ðFig. 124 A or ðFig. 125 by turn-
indicator lamp /
comes on again,
ing it anti-clockwise ð
.
stop the vehicle and switch off the ignition.
Seek professional assistance.
►
►
►
Add coolant in the correct concentration
ðpage 240 up to mark 1 .
You should make sure that the fluid level re-
mains stable. If necessary, add more coolant.
Screw the cap on clockwise until you feel the
second point of resistance.
– If too much coolant has been added to the
coolant expansion tank, drive to a qualified
workshop soon and have the coolant level
corrected.
– If you use non-distilled water, the chemicals
that it contains can cause serious corrosion
damage to the engine – risk of engine dam-
age!
WARNING
– The engine compartment of any motor vehi-
cle is a potentially hazardous area. Before
carrying out any work in the engine com-
partment, switch off the vehicle and allow
the cooling system to cool down. Please ob-
serve the important safety warnings
– If you have used a large quantity of non-dis-
tilled water (more than 0.5 ltr.) in an emer-
gency, drive directly to a qualified workshop
and have the coolant changed.
– Applies to vehicles with mild hybrid technol-
ogy: The caps for the two coolant expansion
tanks must not be swapped over – risk of
engine damage! Black cap for combustion
engine ðFig. 124, blue cap for electrical
components ðFig. 125.
ðpage 235, Safety information on the en-
gine compartment.
– Never open the bonnet if you can see or hear
steam or coolant escaping from the engine
compartment; there is a risk of being scal-
ded. The cooling system is under pressure.
243
English 
