Porsche 911 2020, Owner'S Manual

Page: 78 / 360

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Brakes
76
effects of corrosion depend on the amount of time
the vehicle was parked, whether road salt or grit was
spread and whether grease-dissolving agents were
used in car washes.
If the braking comfort is noticeably impaired, it is
recommended having the brake system checked by
experts at an authorized Porsche dealer.
Brake system function
Porsche sports cars are equipped with a power as-
sisted hydraulic dual circuit brake system with disk
brakes at the front and rear.
Both circuits function independently. One brake cir-
cuit operates the front left and rear right wheel and
the other operates the front right and rear left wheel.
If one brake circuit has failed, the other will still op-
erate. 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.
Responding to warning symbols
The functionality of the brake system warning light
can be checked by switching the ignition to the "On"
position (position 1 ) and verifying that the warning
light illuminates.
Brake warning light USA
Brake warning light Canada
The warning light in the instrument panel lights up. A
message will be displayed on the multi-function
display of the instrument panel if the brake fluid level
is too low, or (if the brake pedal travel has increased)
one of the two brake circuits has failed. A greater
braking pressure will be required, stopping distances
will be longer and the braking behavior will change,
particularly in curves.
Brake components
WARNING
Blocked pedals
Unsuitable or improperly secured floor mats can re-
strict pedal travel or interfere with pedal operation.
The accelerator can be inadvertently actuated or the
brake pedal blocked. This can result in an unex-
pected increase in speed or make braking more
difficult.
e Only use floor mats that are suitable for the
vehicle.
e Secure floor mats properly and do not place them
loosely on the floor.
e
Do not lay several floor mats on top of each
other.
e
Ensure that the floor mats are securely fitted
again after they have been removed, e.g. for
cleaning.
WARNING
No brake force boosting
The brake booster is ready for operation only when
the engine is running. If the engine is switched off or
there is a defect in the brake booster, much greater
force has to be applied to the pedal when braking.
e Vehicles with defective brakes must not be
towed.
WARNING
Water film on brake
discs
In case of heavy rain, water crossing or after a car
wash, the braking action may be delayed and
increased foot pressure may be required.
e Check the brakes after washing the vehicle.
e For this reason, keep further back from the ve-
hicle in front and “dry” the brakes by applying
them at intervals. Make sure that the traffic be-
hind you is not affected.
WARNING
Reduced braking action
After a long drive over salted or gritted roads, a
coating may form on the brake discs and pads that
significantly reduces friction and therefore also
braking effect.
The brake discs will unavoidably start to corrode if
your vehicle is parked for an extended period. The
brakes will tend to “judder” as a result.
e If braking comfort is noticeably impaired, it is
recommend that you have the brake system
checked by experts.
Visit a qualified specialist workshop. Porsche
recommends an authorized Porsche dealer as
they have trained workshop personnel and the
necessary parts and tools.
e To relieve the brake system on steep slopes, re-
member to shift to a lower gear in good time
(engine braking effect). If the engine braking ef-
fect on slopes is not sufficient, use the footbrake
at intervals. Continuous braking can cause the
brakes to overheat, impairing their effectiveness.
For information on brake fluid and checking the
brake fluid level:
> Please see chapter "Brake Fluid" on page 74.
With correctly adjusted brakes and a correctly
working brake system, the pedal travel to the point
of brake application (start of brake pressure build-
up) should not be longer than 10 mm.