Brakes - Volvo S80 Owner's Manual

Brake system
The brake system is a hydraulic system con-
sisting of two separate brake circuits. If a
problem should occur in one of these cir-
cuits, it is still possible to stop the vehicle
with the other brake circuit.
If the brake pedal must be depressed farther
than normal and requires greater foot pres-
sure, the stopping distance will be longer.
A warning light in the instrument panel will
light up to warn the driver that a fault has
occurred.
If this light comes on while driving or braking,
stop immediately and check the brake fluid
level in the reservoir.
NOTE
Press the brake pedal hard and maintain
pressure on the pedal - do not pump the

brakes.

WARNING
If the fluid level is below the MIN mark in the
reservoir or if a brake system message is
shown in the information display: DO NOT
DRIVE. Have the vehicle towed to a trained
and qualified Volvo service technician and
have the brake system inspected.
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, the
brake pedal must be pressed approximately
five times harder than usual to make up for
the lack of power assistance. This can hap-
pen for example 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
washing or starting in very damp or cold
weather.
03 Your driving environment
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 usu-
ally 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.
Anti-lock braking system
The Anti-lock Braking System (ABS) helps to
improve vehicle control (stopping and steer-
ing) during severe braking conditions by lim-
iting brake lockup. When the system
"senses" impending lockup, braking pres-
sure is automatically modulated in order to
help prevent lockup that 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.

Brakes

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