Volvo XC90 Owner's Manual page 157

WARNING
•
Use the jack intended for the vehicle
when changing a tire. For any other
job, use stands to support the vehicle.
•
The jack should be kept well-greased
and clean, and should not be dam-
aged.
•
Be sure the jack is on a firm, level,
non-slippery surface.
•
No objects should be placed between
the base of jack and the ground, or
between the jack and the attachment
bar on the vehicle.
•
The jack must correctly engage the
jack attachment.
•
Never allow any part of your body to
be extended under a vehicle suppor-
ted by a jack.
Power brakes function only when the
engine is running
The power brakes utilize vacuum pressure
which is only created when the engine is run-
ning. Never let the vehicle roll to a stop with
the engine switched off.
If the power brakes are not working, consid-
erably higher pressure will be required on the
brake pedal to compensate for the lack of
power assistance. This can happen for exam-
ple when towing your vehicle or if the engine
is switched off when the vehicle is rolling. The
brake pedal feels harder than usual.
Water on brake discs and brake pads
affects braking
Driving in rain and slush or passing through
an automatic car wash can cause water to
collect on the brake discs and pads. This will
cause a delay in braking effect when the
pedal is depressed. To avoid such a delay
when the brakes are needed, depress the
pedal occasionally when driving through rain,
slush etc. This will remove the water from the
brakes. Check that brake application feels
normal. This should also be done after wash-
ing or starting in very damp or cold weather.
Severe strain on the brake system
The brakes will be subject to severe strain
when driving in mountains or hilly areas, or
when towing a trailer. Vehicle speed is usually
slower, which means that the cooling of the
brakes is less efficient than when driving on
level roads. To reduce the strain on the
brakes, shift into a lower gear and let the
engine help with the braking. Do not forget
that, if you are towing a trailer, the brakes will
be subjected to a greater than normal load.
06 Starting and driving
Brake system
Anti-lock brakes (ABS)
If the ABS warning lamp lights up there is a
malfunction in the ABS system (the standard
braking system will however function) and the
vehicle should be driven cautiously to a
trained and qualified Volvo service technician
for inspection. The Anti-lock Braking System
(ABS) helps to improve vehicle control (stop-
ping and steering) during severe braking con-
ditions by limiting brake lockup. When the
system "senses" impending lockup, braking
pressure is automatically modulated in order
to help prevent lockup, which could lead to a
skid.
The system performs a self-diagnostic test
when the engine is started and when the
vehicle first reaches a speed of approxi-
mately 12 mph (20 km/h). The brake pedal
will pulsate several times and a sound may be
audible from the ABS control module. This is
normal.
To obtain optimal effect from the ABS sys-
tem, constant pressure should be kept on the
brake pedal. Do not pump the brake pedal.
The switching of the ABS modulator will be
audible and the brake pedal will pulsate dur-
ing braking. Please be aware that ABS does
not increase the absolute braking potential of
the vehicle. While control will be enhanced,
ABS will not shorten stopping distances on
slippery surfaces.
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