Porsche 2007 Cayenne Owner's Manual page 189

New brake pads or linings
New brake pads have to be "broken in", and there-
fore only attain optimal friction when the car has
covered several hundred miles or km.
The slightly reduced braking ability must be com-
pensated for by pressing the brake pedal harder.
This also applies whenever the brake pads and
brake discs are replaced.
Warning!
f Do not obstruct the pedal travel with floor mats
or other objects.
The brake booster is ready for operation only
while 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.
f Please observe the chapter "TOWING" on
Page 394.
In heavy rain, while driving through water or after
leaving a car wash, the braking action may be de-
layed and increased pressure may be required.
f For this reason, keep further back from the ve-
hicle in front and "dry" the brakes by applying
them at intervals. Make sure that following traf-
fic is not affected.
After a long drive over salted or gritted roads, a
coating may form on the brake discs and pads
that significantly reduces friction and thus braking
action.
f Therefore, clean the brake discs and pads ap-
prox. every 2 weeks with a strong jet of water.
The cleaning effect of automatic car washes is
insufficient.
To prevent corrosion of the brake discs, "brake
them dry" before parking the car.
f 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 re-
sult.
The nature, extent and effects of corrosion de-
pend 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,
we recommend having the brake system
checked by experts at an authorized Porsche
dealer.
f To relieve the braking system on downhill
stretches, change down to a lower gear in
good time to obtain engine braking.
If engine braking is insufficient on steep
stretches, operate the footbrake at intervals.
Continuous braking overheats the brakes and
reduces the braking effect.
f Please observe the chapter "BRAKE-FLUID LE-
VEL" on Page 291.
Driving and Driving Safety
189