maintenance MERCEDES-BENZ METRIS 2020 MY20 Operator’s Manual

the coolant system and reduce the engine's
service life.
The coolant is a mixture of water and anti-
freeze and corrosion inhibitor. It performs the
following tasks:
R Anti-corrosion protection
R Antifreeze protection
R Raises the boiling point
When the vehicle is first delivered, it is filled
with a coolant mixture that ensures adequate
antifreeze/corrosion protection. Coolant must
remain in the engine cooling system all year
round to ensure anti-corrosion protection and
a higher boiling point, even in countries with
high outside temperatures.
Check the antifreeze/corrosion inhibitor con-
centration in the coolant every six months.
The percentage of corrosion inhibitor/anti-
freeze additive in the engine cooling system
should:
R be at least
50%. This way, the engine cooling
system is protected against freezing down
to approximately -35 ‡ (-37 †).
R not exceed 55% (antifreeze protection down
to -49 ‡ [-45 †]). Otherwise, heat will not
be dissipated as effectively.
Mercedes-Benz recommends an antifreeze and
corrosion inhibitor that meets the require-
ments in the Mercedes-Benz Specifications for
Service Products Sheet Number 325.
More information can be obtained at any quali-
fied specialist workshop.
Operating fluid: coolant Product name/number
Zerex G40-91, The Valvoline Company
MB Sheet No. 325.5
Maintenance interval
Have the coolant replaced at specified inter-
vals by a qualified specialist workshop.
Capacities Engine cooling system
Coolant
Approx. 11 US qt
(10.4 l
) Climate control system refrigerants
Important safety notes The climate control system of your vehicle is
filled with the refrigerant R ‑134a.
The warning label for the refrigerant being
used can be found on the radiator cross mem-
ber.
! 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 dam-
aged.
Maintenance work such as adding refrigerant
or replacing components may only be carried
out by a qualified specialist workshop. All
applicable regulations thereto and the SAE
standard J639 must be adhered to.
All work on the climate control system should
always be carried out at qualified specialist
workshop.
Refrigerant warning label Refrigerant warning label (example)
: Warning symbols
; Refrigerant capacity
= Applicable standards
? Part number PAG oil
A Type of refrigerant
The symbol : refers to:
R possible dangers
R the implementation of maintenance work at
a qualified specialist workshop Service products and capacities
311
Technical data Z