Where possible, let the engine cool down andtouch only the components described in the
following.
GWARNING
The engine compartment contains moving
components. Certain components, such as
the radiator fan, may continue to run or start
again suddenly when the ignition is off. There is a risk of injury.
If you need to do any work inside the engine
compartment:
Rswitch off the ignition
Rnever reach into the area where there is a
risk of danger from moving components,
such as the fan rotation area
Rremove jewelry and watches
Rkeep items of clothing and hair, for exam-
ple, away from moving parts
GWARNING
The cooling system is pressurized, particularly
when the motor is warm. If you open the cap,
you could be scalded if hot coolant sprays out.
There is a risk of injury.
Let the engine cool down before you open the
cap. Wear gloves and eye protection. Slowly
open the cap to relieve pressure.
GWARNING
Opening the hood when the engine is over-
heated or when there is a fire in the engine
compartment could expose you to hot gases
or other service products. There is a risk of
injury.
Let an overheated engine cool down before
opening the hood. If there is a fire in the
engine compartment, keep the hood closed
and contact the fire department.
Checking coolant level
Checking the coolant level (example)
XPark the vehicle on a level surface.
Only check the coolant level when the vehicle
is on a level surface and the engine has cooled
down.
XTurn the SmartKey to position 2in the igni-
tion lock (Ypage 127).
or
XPress the Start/Stop button twice on vehicles
with KEYLESS-GO or the KEYLESS-GO start
function (
Ypage 128).
XCheck the coolant temperature display in the
instrument cluster (Ypage 35).
The coolant temperature must be below
158 ‡ (70 †).
XTurn the SmartKey to position gin the igni-
tion lock (Ypage 127).
or
XPress the Start/Stop button once on vehicles with KEYLESS-GO or the KEYLESS-GO start
function (
Ypage 128).
XSlowly turn cap :half a turn counter-clock-
wise and allow excess pressure to escape.
XTurn cap :further counter-clockwise and
remove it.
If the coolant is at the level of marker bar =
in the filler neck when cold, there is enough
coolant in coolant expansion tank ;.
If the coolant level is approximately 0.6 in
(1.5 cm) above marker bar =in the filler neck
when warm, there is enough coolant in expan-
sion tank ;.
XIf necessary, add coolant that has been tested
and approved by Mercedes-Benz.
XReplace cap :and turn it clockwise as far as
it will go.
For further information on coolant, see
(
Ypage 362).
Engine compartment303
Maintenance and care
Z
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It performs the fol-
lowing tasks:
RAnti-corrosion protection
RAntifreeze protection
RRaising the boiling point
If the coolant has antifreeze protection down to -35 ‡ (-37 †), the boiling point of the coolant
during operation is approximately 266 ‡
(130 †).
The antifreeze concentrate/corrosion inhibitor
concentration in the engine cooling system
should:
Rbe at least 50%. This will protect the engine
cooling system against freezing down to
approximately -35 ‡ (-37 †).
Rnot exceed 55% (antifreeze protection down
to -49 ‡[-45 †]) .Otherwise ,hea twill no tbe
dissipated as effectively.
Mercedes-Ben zrecommends an antifreeze/
corrosion inhibitor concentrat ein accordance
wit hMB Specification sfo rServic eProducts
310.1.
iWhe nth evehicle is first delivered, it is filled
wit h a coolan tmixture that ensures adequat e
antifreez ean danti-corrosio nprotection .
iThe coolan tis checke dwit hever ymainte-
nanc einterval at aqualifie dspecialis twork-
shop.
Filling capacities
ModelCapacity
GLC 300 d4MATIC
Coupe10.6 US qt (10.0l)
Mercedes-AMG
GLC 43 4MATIC
Coupe12.2 US qt (11.5 l)
Allot her models9.5 US qt (9.0 l)
Windshield washer system
Important safety notes
GWARNING
Windshield washer concentrate could ignite if it comes into contact with hot engine compo-
nents or the exhaust system. There is a risk offire and injury.
Make sure that no windshield washer con-
centrate is spilled next to the filler neck.
!Only use washer fluid that is suitable for
plastic lamp lenses, e.g. MB SummerFit or MB
WinterFit. Unsuitable washer fluid could dam-
age the plastic lenses of the headlamps.
!Only MB SummerFit and MB WinterFit
washer fluid should be mixed together. The
spray nozzles may otherwise become
blocked.
Do not use distilled or de-ionized water. Other-
wise, the level sensor may give a false reading.
When handling washer fluid, observe the impor-
tant safety notes on service products
(
Ypage 358).
At temperatures above freezing:
XFill the washer fluid reservoir with a mixture of
water and windshield washer fluid, e.g. MB
SummerFit.
Add 1 part MB SummerFit to 100 parts water.
At temperatures below freezing:
XFill the washer fluid reservoir with a mixture of
water and washer fluid, e.g. MB WinterFit.
For the correct mixing ratio refer to the infor-
mation on the antifreeze reservoir.
iAdd windshield washer fluid, e.g. MB Sum-
merFit or MB WinterFit, to the washer fluid all
year round.
Climate control system refrigerant
Important safety notes
The climate control system of your vehicle is fil-
led with refrigerant R ‑134a.
The instruction label regarding the refrigerant
type used can be found on the radiator cross
member.
!Only the refrigerant R ‑134a and the PAG oil
approved by Mercedes-Benz may be used.
The approved PAG oil may not be mixed with
any other PAG oil that is not approved for
R-134a refrigerant. Otherwise, the climate
control system may be damaged.
Service products and filling capacities363
Technical data
Z
