Nanni N16.900 CR3, Operator'S Manual

Page: 71 / 119

71
CHECKING THE COOLANT
LEVEL
WARNING !
Do not open the coolant filler cap in the expansion tank if
the engine is hot. Hot coolant and steam may spray out
and cause burns. If the cap has to be opened do it slowly
to release the pressure before removing the cap. Wear
protective gloves as the coolant is still very hot.
IMPORTANT !
It is not permissible to top up large amounts of coolant
via the expansion tank. Filling via the expansion tank
leads to air locks in the cooling system which can lead to
e.g. cavitation damage to the coolant pump shaft seal. If
a large amount of coolant needs to be added, follow the
instructions in the section Filling coolant. Only pour pre-
mixed coolant into the cooling system.
1. Check the coolant level through the sight
glass on the expansion tank.
2. Top up with coolant as necessary.
S08 MAINTENANCE
CHECKING THE COOLANT
ANTI FREEZE AND
CORROSION PROTECTION
Tools required
Designation Illustration
Refractometer
IMPORTANT !
Use only pure fresh water that is free from particles,
sludge and other impurities.
1. Pour a small amount of coolant into a container and
check that the coolant is pure and clear.
2. Change the coolant if it is contaminated or cloudy.
3. Measure the antifreeze content with a refractometer.
The following rules apply to ethylene glycolbased cool-
ant:
• The antifreeze and corrosion protection content must
be a minimum of 35 per cent by volume for corrosion
protection to be sufficient.
• An antifreeze and corrosion protection content greater
than 55 per cent by volume impairs the ability to protect
from frost.
• If ice forms in the coolant, there are disruptions initially,
but there is no immediate risk of damage. The engine
should not be subjected to heavy loads when ice starts
to form.