Mercedes-Benz GLK 300 4MATIC 2012 Owner's Manual page 374

used. The low-temperature properties of
engine oils can be significantly impaired dur-
ing operation due to, for example, ageing or
soot and fuel accretion. It is therefore
strongly recommended to observe regular oil
changes using an approved engine oil with the
appropriate SAE classification.
Brake fluid
G WARNING
Over a period of time, the brake fluid absorbs
moisture from the air; This lowers its boiling
point.
If the boiling point of the brake fluid is too low,
vapour pockets may form in the brake system
when the brakes are applied hard (e.g. when
driving downhill). This impairs braking effi-
ciency.
You should have the brake fluid renewed at
regular intervals. The brake fluid change inter-
vals can be found in the Service Booklet.
Only use brake fluid approved by Mercedes-
Benz according to MB Approval 331.0.
Information about approved brake fluid can
be obtained at any qualified specialist work-
shop or on the Internet at
http://bevo.mercedes-benz.com.
i
Have the brake fluid renewed regularly at
a qualified specialist workshop.
Coolant
Important safety notes
G WARNING
Antifreeze is highly flammable. Fire, naked
flames and smoking are prohibited when han-
dling antifreeze.
If antifreeze comes into contact with hot
engine parts, it may ignite and you could burn
yourself. Do not spill any antifreeze on hot
engine parts.
Service products and capacities
! Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise damage the engine.
Further information on coolants can be
found in the Mercedes-Benz Specifications
for Service Products, MB Specifications for
Service Products 310.1, e.g. on the Inter-
net at http://bevo.mercedes-benz.com.
Or contact a qualified specialist workshop.
! Always use a suitable coolant mixture,
even in countries where high temperatures
prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
! The engine cooling system is filled with
coolant, which must be renewed after
15 years or after 250,000 kilometres at the
latest.
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It performs the
following tasks:
anti-corrosion protection
R
antifreeze protection
R
raising the boiling point
R
If antifreeze/corrosion inhibitor is present in
the correct concentration, the boiling point of
the coolant during operation will be approx-
imately 130 †.
The antifreeze/corrosion inhibitor concentra-
tion in the engine cooling system should:
be at least 50%. This will protect the engine
R
cooling system against freezing down to
approximately -37 †.
not exceed 55% (antifreeze protection
R
down to -45 †). Heat will otherwise not be
dissipated as effectively.
If the vehicle has lost coolant, top it up with
equal amounts of water and antifreeze/cor-
rosion inhibitor. Mercedes-Benz recom-
mends an antifreeze/corrosion inhibitor con-
centrate in accordance with MB Specifica-
tions for Service Products 310.1.
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