Volvo XC90 Owner's Manual page 222

09 Maintenance and servicing
Working on your vehicle
09
Belt check
Check the belt regularly to make sure it is in
good condition and is clean. A worn or dirty
belt can cause poor cooling and low alterna-
tor output as well as impair the operation of
the power steering and the air conditioning
unit.
NOTE
The drive belt is equipped with a self-ten-
sioning mechanism and requires no
adjustment between changes.
WARNING
The engine must not be running when this
check is performed.
Check coolant level
The cooling system must be filled with cool-
ant and not leak to operate at maximum effi-
ciency. Check the coolant level regularly. The
level should be between the MAX and MIN
marks on the expansion tank. The check
should be made with particular thoroughness
when the engine is new or when the cooling
system has been drained.
Do not remove the filler cap other than for
topping up with coolant. Frequent removal
may prevent coolant circulation between the
220
engine and the expansion tank during engine
warm up and cooling.
Changing coolant
Normally, the coolant does not need to be
changed. If the system must be drained, con-
sult a trained and qualified Volvo service
technician.
Do not top off with water only. This reduces
the rust-protective and antifreeze qualities of
the coolant and has a lower boiling point. It
can also cause damage to the cooling system
if it should freeze. Top off with Volvo Genuine
Coolant/Antifreeze only (a 50/50 mix of water
and antifreeze.
CAUTION
The cooling system must always be kept
filled to the correct level. If it is not kept
filled, there can be high local temperatures
in the engine which could result in dam-
age. Different types of antifreeze/coolant
may not be mixed.
WARNING
•
Never remove the expansion tank cap
while the engine is warm. Wait until the
engine cools.
•
If it is necessary to top off the coolant
when the engine is warm, unscrew the
expansion tank cap slowly so that the
overpressure dissipates.