PORSCHE 911 GT3 2004 5.G Service Manual

ClutchPedal

The clutch pedalmustbedepressed fully
before thestarter willengage.

A
Warning!
Risk ofan accident.

\>
Always checkthemovement ofthe clutch ped-
al before driving andmake surethatitis not
obstructed byafloor matorany other object.

\>
Secure thefloor mattoprevent itfrom sliding
into positions thatcould interfere withthesafe
operation ofyour vehicle.
Your Porsche dealerwillbeglad tooffer you
floor mats ofthe correct sizeincluding asecur-
ing possibility.

To avoid damage tothe clutch andtransmis-
sion:

\>
Always depress theclutch pedalfullywhen
changing gears.

\>
Donot hold thecar onasteep grade withthe
clutch pedalpartially depressed.
Should thefree travel ofthe clutch pedalsuddenly
become bigger,itcould mean amalfunction ofthe
clutch.

\>
See your Porsche dealerforcorrection.

40
Controls, Instruments
Parking
Brake

Parking brakeforceismechanically transferredto
the rear wheels bymeans ofcables.

\>
Use theparking brakeonlyafter thevehicle
has come toafull stop.
Setting
theparking brake

\>
Pull thelever
allthe way up(arrow).

With theignition on,the parking brakewarning
lights inthe instrument panelandon-board
computer willcome onifthe lever iseven
slightly raised.Afirm pullupward isrequired to
properly engagetheparking brake.
If the brake isnot fully set,thevehicle mayroll
without control.

\>
Move thegearshift levertoreverse orfirst
gear.

\>
Before exitingthevehicle, makesurethatthe
parking brakeisfully setand thevehicle isnot
moving atall.

Releasing theparking brake

\>
Pull thelever slightly upasyou depress there-
lease button
A,
and then push thelever allthe
way down.

Parkingbrakewarning lightUSA
Parking brakewarning light
Canada

The warning lightsinthe instrument panelandon-
board computer willgoout after theparking brake
is fully released.
The warning lightsarenotanindicator thatthe
parking brakeisfully set;itis only intended tobe
a warning torelease theparking brakebefore
driving thecar.

A
Caution!
A partially engaged brakewilloverheat the
rear brakes, reducetheireffectiveness and
cause excessive wear.

~ Release theparking brakefully.
t> When parking yourcar,always setthe parking
brake bypulling allthe way uponthe lever.

t>
Move thegearshift levertoreverse orfirst
gear.

t>
Onhills also turnthefront wheels towards the
curb.
Brakes

t>
Please observe thechapter "AERODYNAMIC
COMPONENTS" onPage 9.

t>
Make itahabit tocheck theoperation ofyour
brakes beforedriving.
Keep inmind thatthebraking distance increases
very rapidly asthe speed increases. At60 mph or
100 km/h, forexample, itis not twice butfour
times longer than30mph or50 km/h. Tiretrac-
tion isalso lesseffective whentheroads arewet
or slippery.

t>
Therefore, alwaysmaintain asafe distance
from thecarinfront ofyou.

Vehicles withoutPorsche Ceramic Compos-
ite Brake (PCCB)

Even though thebrake discsconsist ofalloyed
grey castiron,theywillunavoidably starttocor-
rode ifyour carisparked foranextended period.
The brakes willtend to"rub" asthe result.
The nature, extentandeffects ofcorrosion de-
pend onthe amount oftime thevehicle was
parked, whether granular orliquid roadsaltwas
spread andwhether grease. were usedincar washes.
If the braking comfort isnoticeably impaired,we
recommend havingthebrake system checked by
experts atan authorized Porschedealer.
Brake
system function

Your Porsche isequipped withapower assisted
hydraulic dualcircuit brakesystem withdisc
brakes atthe front andrear.
Both circuits function independently. Onebrake
circuit operates thefront andtheother operates
the rear.
If one brake circuit hasfailed, theother willstill op-
erate. However, youwillnotice anincreased pedal
travel whenyouapply thebrakes.
Failure ofone brake circuit willcause thestopping
distance toincrease.

A
Warning!
Risk ofan accident.
In the unlikely eventofhydraulic failureof
one brake circuit:

t> Push thebrake pedaldownfirmly andhold itin
that position.
A mechanical linkageactivates thesecond cir-
cuit, andyou willbeable tobring thevehicle to
a stop.
t> After bringing yourvehicle toacomplete stop,
avoid driving thevehicle andinstead haveit
towed tothe nearest authorized Porschedeal-
er for repair.
Controls,Instruments

•Brakewarning lightUSA
~ Brakewarning lightCanada

If the warning lightsinthe instrument panelandon-
board computer goonwhile driving, thebrake flu-
id level maybetoo low, or(ifthe brake pedaltrav-
el has increased) oneofthe two brake circuits
may have failed.
A greater braking pressure willberequired, stop-
ping distances willbelonger andthebraking be-
havior willchange, particularly incurves.
With correctly adjustedbrakes,andacorrectly
working brakesystem, thepedal travel tothe
point ofbrake actuation shouldbe1-3/16 in.to
1-9/16 in.or30 to40 mm.
Whenever thebrake pedaltravel exceeds thisdis-
tance, havethebrake system checked.

42
Controls, Instruments
Brake
pedal

A
Warning!
Risk ofan accident.
Any obstruction ofthe brake pedalcould
increase thestopping distance.

~ Always checkthemovement ofthe brake ped-
al before driving andmake surethatitis not
obstructed byafloor matorany other object.
~ Secure thefloor mattoprevent itfrom sliding
into positions thatcould interfere withthesafe
operation ofyour vehicle.
Your Porsche dealerwillbeglad tooffer you
floor mats ofthe correct sizeincluding asecur-
ing possibility.

Note

In case oneofthe two brake circuits fails,in-
creased pedaltravel isrequired tobring your
vehicle toafull stop.
A

Warning!
To avoid overheating andpremature wearof
the brakes:

~ Before descending asteep grade, reduce
speed andshift thetransmission intoalower
gear ordriving position tocontrol speed.
~ Donot "ride thebrakes" byresting yourfooton
the pedal whennotintending toapply brake
pressure.
~ Donot hold thepedal downtoolong ortoo
often.
This could cause thebrakes toget hotand not
function properly.

Brakebooster

The brake booster assistsbraking onlywhen
the engine isrunning.

When thecar ismoving whiletheengine isnot run-
ning, orifthe brake booster isdefective, more
pressure onthe brake pedalisrequired tobring
the car toastop.
Moisture orroad saltonbrakes affects braking.
When thevehicle isdriven onsalted roadsforex-
tended periods, thebrakes shouldbewashed
down thoroughly aboutevery2weeks. Anauto-
matic carwash facilitycannot dothis jobproperly.
Brakes willdry after afew cautious brakeapplica-
tions.

/!\.
Warning!
Driving through watermayreduce thetrac-
tion. Moisture onbrakes fromroadwater, car
wash, orcoating ofroad saltmay affect
braking efficiency.

c>
Cautiously applybrakes totest brakes after
being exposed.
Brake
wear

Your carhas excellent brakes,butthey arestill
subject towear. Therate atwhich theywear de-
pends onhow thebrakes areused.

c>
Have thebrake system inspected atthe
intervals recommended inyour Maintenance
Booklet.

•• Warning lightUSA
• Warning lightCanada

If the warning lightsinthe instrument panelandon-
board computer stayonwhen theengine isrun-
ning orcome onwhile driving, thebrake padsare
worn, excessively.

c>
Donot continue tooperate thevehicle.
Have yourauthorized Porschedealerinspect
or replace thebrake pads.
Brake
pads

Wear onthe brake padsandbrake discsdepends
to agreat extent onthe driving styleandthecon-
ditions ofuse and therefore cannotbeexpressed
in actual milesonthe road.
The high-performance brakesystem isdesigned
for optimal braking effectatall speeds andtem-
peratures.
Certain speeds, brakingforcesandambient
conditions (suchastemperature andhumidity)
therefore mightcause "brake noises".

New brake padsorlinings

New brake padsandbrake discshavetobe "bro-
ken i",and therefore onlyattain optimal friction
when thecar has covered severalhundred miles

or km.

The slightly reduced brakingabilitymustbecom-
pensated forbypressing thebrake pedalharder.
This alsoapplies whenever thebrake padsand
brake discsarereplaced.
Controls, Instruments
43

ABSBrake System
(Antilock BrakeSystem)

The ABS system represents amajor contribution
to the enhancement ofactive safety inyour vehi-
cle. This system prevents thewheels fromlocking
in apanic stoponalmost allroad surfaces.
Controls, Instruments
With
theASS system inyour vehicle, the
following areasareenhanced:
Steering,
vehicleremains steerable underall
braking forceswhenABSisengaged.

Good directional control,
noswerving caused
by locking ofwheels underbraking conditions.

Shorter stopping distance,
stoppingdistances
are usually reduced because controlled brakingis
maximized.

Prevention of
wheel lock
up,
nobrake- induced
sliding andthus nolocalized tirewear fromemer-
gency braking.
The crucial advantage ofthe ABS system overa
conventional brakesystem isinthe area ofmain-
taining directional controlandmaneuverability of
the car inemergency situationsduringnormal
driving, including panicbraking inturns.
A

Warning!
The increased controlthatisprovided should
not induce youtotake greater riskswithyour
safety. Thelimits dictated bythe laws of
physics cannotbeovercome, evenwithASS.
The riskofaccidents duetoinappropriate
speed cannot bereduced, evenbythe ASS.
The driver bearstheresponsibility forall
driving maneuvers.

t>
Adapt yourdriving styletothe prevailing road
and weather conditions.
t> Obey alltraffic laws.

Other vehicles notequipped withtheASS
system maynotbeable tomaintain control,
especially onwet orpoor roadsurfaces and
thus maybemore likelytoimpact youfrom
behind.

t>
Tominimize thatrisk, useyour ABSsystem to
increase yourability tomaneuver toavoid dan-
gerous situations andnotmerely totry tostop
in the shortest distance possible.

Operation ofthe ABS system
A wheel speed sensor ismounted toeach ofthe
four wheels. Ifwheel lock-up ofeither ofthe front
wheels orthe rear wheels issensed duringbrak-
ing, thebrake pressure isadjusted automatically
until thewheel nolonger slips.Thebrake pressure
is regulated foreach frontwheel individually and
for both ofthe rear wheels together.
On aroad surface whichisslippery ononly one
side, therear wheel whichisbraking onthe slip-
pery surface determines thebrake pressure which
will beapplied equallytoboth rearwheels. Thisen-
sures thatdirectional stabilityismaintained. How-
ever, ifbraking forcesapproach thewheel lock-up
point forallwheels (panicbraking) theABS system
will intervene toprovide arapid rythmic braking.
The proper operation ofABS isperceived bythe
driver asapulsating brakepedalinconjunction
with audible noiseandperhaps somevibration.

I>
Ifyou experience thesesensations whiledriv-
ing oraroad surface withquestionable trac-
tion, reduce vehicle speedappropriate forthe
prevailing roadconditions.
The functional readinessofall the main electrical
components ofthe ABS ischecked byan
electronic monitoring systembothbefore and
while youdrive. •
Warning lightUSA
• Warning lightCanada
When theignition isswitched onthe ABS warning
light willlight upwhile thesystem iselectronically
interrogated andgoes outwhen theengine is
started ifthe check isnot yetcomplete.
If the ABS warning lampfailstogo out, thisindi-
cates thatABS hasbeen deactivated duetoa
fault. Ifthe warning lightsinthe instrument panel
and on-board computer lightupwhile youaredriv-
ing, this indicates thatafault hasoccurred. Inboth
cases, normal braking, asinvehicles withoutABS,
is still retained.
The ABS system should,however, beexamined at
an authorized Porschedealerimmediately topre-
vent theoccurrence offurther faults.

I>
Ifthe ABS system becomes inoperative, take
your vehicle toyour authorized Porschedealer
immediately.
A

Warning!
The control unitofthe ABS brake system is
set forstandard tiresize. Ifnon-standard
tires areinstalled, thecontrol unitmay mis-
interpret thespeed ofthe vehicle, because of
the variant dataitreceives fromthesensors
on the axles.

I>
Use only tiremakes andtypes tested by
Porsche.
Controls,Instruments

A,
D-$witch forreading light
on
driver's/
passenger's side

B -
Interior lightswitch

C -
Orientation lightswitch

E -
Orientation light

Interior lights

l>
Please observe thechapter "LOADSWITCH-
OFF AFTER TWOHOURS ORFIVE DAYS" on
Page 152.

46
Controls, Instruments
Interior
light,reading lights

Switching off

l>
Press lefthalf ofswitch.

Switching tocontinuous illumination

l>
Press righthalfofswitch_

Switching onand offautomatically

l>
Move switch tocenter position.
The lights are
switched on
when adoor is
unlocked oropened orwhen theignition keyis
withdrawn fromtheignition lock.
The lights are
switched off
with adelay ofap-
prox. 30seconds afterthedoor isclosed.
The light goes outimmediately assoon asthe
ignition keyisinserted inthe ignition lockor
the vehicle islocked.
Orientation
light

Light-emitting diodesinthe doors andinthe
interior lightimprove yourorientation insidethe
vehicle whenitis dark.
The light-emitting diodesareswitched onwhen the
vehicle isunlocked andswitched offagain when
the vehicle islocked.

Light-emitting diodeinthe interior light

Changing thebrightness ofthe light-emitting
diode:

l>
Press switch Cwith apointed object(suchas
a ball-point pen).
The brightness changes.

:8:
Footwell Lights

The lights areswitched onautomatically whena
door isopened andgoout with adelay ofapprox.
30 seconds afterthedoor isclosed.

Switching tocontinuous illumination

l>
Press therocker-switch symbolinthe center
console. Indicator lightcomes on.
The lights between thesun visors andthedoor
guard lightsareswitched onadditionally. The
lights areautomatically switchedoffafter approx.
12 minutes inorder tosave thevehicle battery.
The lights canbeswitched backonbypressing
the rocker switchagain.

Switchinglightsoff

l>
Press theindicator lightinthe rocker switch.
Controls,Instruments
47

Operation, Instruments

1 Side vent
2 Ignition/starter switchwithsteering lock
3 Space forhands-free microphone for
telephone
4 Turn signals/
headlight dimmer/flasher lever
5 Instrument panel
6 Horn
7 Windshield wiper/washer lever
8 Emergency flasherswitch
9 Rocker switches forfootwelilight
10 Readiness displayforalarm system
11 Central vent
12 Cupholder
13 Control panelforheating, ventilation,
air conditioning
14 Rocker switches for
central locking,
rear window anddoor mirror heating

48
Controls, Instruments 15
Speaker
16 Light switch
17 Operating leverforon-board computer
18 Locking leverforsteering-wheel adjustment
19 Operating leverforautomatic speedcontrol
20 Wipe interval control
21 Radio
22 Cigarette lighter
23 Glove compartment
24 Interior temperature sensor

Controls,Instruments