Porsche 911 Carrera - Manual (Page 74)

Brakes
General information
Make it a habit to check the operation of your
brakes before driving.
Keep in mind that the braking distance increases
very rapidly as the speed increases. At 60 mph
or 100 km/h, for example, it is not twice but four
times longer than 30 mph or 50 km/h. Tire traction
is also less effective when the roads are wet or
slippery.
Therefore, always maintain a safe distance
from the car in front of you.
Vehicles without Porsche Ceramic
Composite Brake (PCCB)
Even though the brake discs consist of alloyed
grey cast iron, they will unavoidably start to
corrode if your car is parked for an extended
period. The brakes will tend to “rub” as a result.
The nature, extent and effects of corrosion depend
on the amount of time the vehicle was parked,
whether granular or liquid road salt was spread
and whether grease-dissolving agents were used
in car washes. If the braking comfort is noticeably
impaired, we recommend having the brake system
checked by experts at an authorized Porsche
dealer.
Brake system function
Your Porsche is equipped with a power assisted
hydraulic dual circuit brake system with disc
brakes at the front and rear. Both circuits function
independently. One brake circuit operates the front
and the other operates the rear.
If one brake circuit has failed, the other will still
operate. However, you will notice an increased
pedal travel when you apply the brakes. Failure of
one brake circuit will cause the stopping distance
to increase.
Warning!
Risk of an accident, resulting in serious
personal injury or death. In the unlikely event
of hydraulic failure of one brake circuit:
Push the brake pedal down firmly and hold it in
that position. A mechanical linkage activates
the second circuit, and you will be able to bring
the vehicle to a stop.
After bringing your vehicle to a complete stop,
avoid driving the vehicle and instead have
it towed to the nearest authorized Porsche
dealer for repair.
Brake warning light USA
Brake warning light Canada
If the warning lights in the instrument panel and
on-board computer go on while driving, the brake
fluid level may be too low, or (if the brake pedal
travel has increased) one of the two brake circuits
may have failed.
A greater braking pressure will be required,
stopping distances will be longer and the braking
behavior will change, particularly in curves.
With correctly adjusted brakes, and a correctly
working brake system, the pedal travel to the
point of brake actuation should be 1-3/16 in. to
1-9/16 in. or 30 mm to 40 mm. Whenever the
brake pedal travel exceeds this distance, have the
brake system checked.
Brake pedal
Warning!
Risk of an accident, resulting in serious
personal injury or death. Any obstruction of
the brake pedal could increase the stopping
distance.
Always check the movement of the brake
pedal before driving and make sure that it is
not obstructed by a floor mat or any other
object.
72
Controls, Instruments