Coolants - Mercedes-Benz 300SD 1981 Owner's Manual

Fuels C o o lants Lubricants etc.

Coolants

The coolant is a mixture of water and
antifreeze. In production, the cooling
system is filled with an antifreeze-
water mixture offering protection to
approx. - 3 0 ° C /- 2 2 ° F.The red
mark on the temperature gauge in the
instrument cluster is matched to this
antifreeze-water mixture (approx.
boiling point 125° C/257° F). The
protection against corrosion is also
ensured by this mixture making it
unnecessary to add a corrosion
inhibitor.
The coolant remains in the cooling
system all year long and must be
renewed after 3 years at the latest.
If coolant is lost, replace missing
quantity with water (potable water
quality) plus antifreeze of a recom­
mended brand.
For reasons of corrosion inhibition
the minimum proportion of antifreeze
must be 34 % , which gives antifreeze
protection down to —20° C/ —4° F.
If antifreeze is not available, add a
corrosion inhibitor to the cooling
water to ensure proper protection
against corrosion. To treat the cooling
water, do not use more than 1 %
(10 cm3/l) of a recommended corro­
sion inhibitor.
Without antifreeze in the cooling
system, the water already starts
boiling at approx. 118° C/224° F,
which means that the pointer of the
temperature gauge in the instrument
cluster may still be below the red
mark.
Antifreeze
Your vehicle contains a number of
aluminium parts. The use of alumin­
ium components in motor vehicle
engines necessitates that antifreeze/
coolant used in such engines be
specifically formulated to protect the
aluminium parts. (Failure to use such
antifreeze/coolant may result in a
significantly shortened service life.)
While there may be a number of
antifreeze/coolants available which
will provide the requiste protection, all
such products have not been tested
for MERCEDES-BENZ vehicles. The
following products, however, are
deemed suitable for use in your car:
MERCEDES-BENZ Anti-Freeze and
Summer Coolant.
Prior to the onset of the cold season,
check the coolant for its resistance to
cold. Repeat this check during the
cold spell. Regular testing of the
antifreeze concentration is carried
out only at each MERCEDES-BENZ
maintenance service.
Protection
up to________ Antifreeze__________
- 2 0 ° C 4.50 I
- 4° F 4.8 US qt
- 3 0 ° C 5.50 I
- 2 2 ° F 5.8 US qt
- 4 0 ° C 6.50 I
- 4 0 ° F 6.9 US qt