Cooling And Heating System; Checking For Leaks And General; Condition - Mercedes-Benz OM 904 LA Operating Instructions Manual

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Only check and correct the coolant lev-
el when the coolant temperature is
below 50 °C. Check the antifreeze/
corrosion inhibitor concentration be-
fore correcting the coolant level. Only
use a prepared coolant for topping up
with an antifreeze/corrosion inhibitor
concentration of 50% by volume.
Open the engine cooling system cap
slowly, relieving the excess pressure.
Check the antifreeze/corrosion inhibi-
tor concentration using a testing
device. The specified antifreeze/ corro-
sion inhibitor concentration of 50% by
volume is present if antifreeze protec-
tion is ensured down to –37 °C. If less
antifreeze protection is displayed, cor-
rect the mixing ratio.
!
If the concentration is too low, there is
a risk of engine damage as a result of
corrosion/cavitation in the cooling
system.
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Avoid antifreeze/corrosion inhibitor
concentrations of more than 55% by
volume, otherwise maximum antifreeze
protection down to –45 °C will not be
achieved. Heat dissipation and anti-
freeze protection deteriorate at higher
concentrations.
Check the coolant level.
The cooling system is correctly filled if
the coolant reaches the mark in the fill-
er neck.
Maintenance
Work schedules

Cooling and heating system:

checking for leaks and general

condition

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The "Engine cooling system: checking
and correcting the fluid level and
antifreeze/corrosion inhibitor" opera-
tion must have already been carried
out.
Carry out a visual inspection of the
radiator for leaks and damage.
!
If damage/faults are detected, repair
the radiator or replace it.
Check the radiator for external dirt. The
fins must not be dirty.
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