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Brake - A8 Parts Forum

1. Removing and installing actuator motor for electronic parking brake and handbrake Brakes hydraulics isa oe ed es ye ale Cs tere aa ew Sd s ode wea ek Pressurised leak test ty ge ccsed 8 Gace dla Bae be lied Bae eae a a ane ed Be Pressunsed leak test ac 034 44 dared a a cen BO a auahal ee dads teed dn a aaa ghee deel ded ad High pressure and low pressure testS 0000 0c eee eee eee Brake calipers FNR G60 1 ene a eee e eens Servicing brake calipers 0000 eee Removing and installing piston for front brake caliper 2220000005 Brake calipers 2FNR 42 AL 2 1 eee Servicing brake calipers 0000s Removing and installing pistons for front brake caliper 22200005 Brembo brake calipers 18 2 naian onnaa e eE Servicing brakefcalipers AAR AY MRA RR eee ee Removing and installing pistons for front brake caliper 200020000e Brake caliper ceramic brakes unnan ccc eee eee eens Servicing brake caliper ceramic brakes 000000 e eee eee eee Removing and installing pistons for front brake caliper 000000000 0 Rear brake calipers for electronic parking brake and handbrake EPB Servicing brake calipers n n nnna aaa a bee eee eee Removing and installing piston for rear brake caliper 0000s Bleeding brake systeM 00 0 cece eet teenies Bleedin
2. Insert speed sensor into hole in wheel bearing housing and tighten bolt together with bracket for speed sensor wire to 10 Nm Connect speed sensor to speed sensor wiring 4 Removing and installing parts of ABS system on front and rear axles 33 N Audi A8 2003 gt Au Brake system Edition 03 2013 5 Removing and installing parts of ESP system 5 1 Removing and installing brake light switch Note The brake light switch must be removed in order to adjust it To ensure a secure fit the switch may only be fitted once Removing Unplug electrical connector Turn brake light switch anti clockwise 45 to remove Installing Installation is performed in reverse sequence note the following Pull out plunger of brake light switch as far as it will go arrow Fitretainer tabs 1 and 2 on switch into recesses in mounting hole Note When installing brake pedal must not be pressed The plunger adjusts itself automatically when the brake light switch is inserted Guide switch through mounting hole press against pedal and secure by turning 45 clockwise Install driver s storage compartment gt Body Repairs Rep gr 68 Storage compartments trim panels and covers Removing and installing driver s storage compartment After adjusting the brake light switch check whether the brake pedal is on the end stop rest position 34 Rep gr 45 Anti lock b
3. Remove hydraulic control unit Installing Installation is performed in reverse sequence note the following a Note Donot remove sealing plugs from new hydraulic unit until cor responding brake line is ready to be fitted fsealing plugs are removed from hydraulic unit sooner brake fluid may escape and it may no longer be possible to fill and bleed the unit properly When assembling control unit and hydraulic unit make sure contact pins of hydraulic unit do not catch on control unit sol enoids 3 Electronic stabilisation program Bosch 5 7 27 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 Connect pipes as previously marked 1 Primary piston circuit 2 To front left brake caliper 3 To front right brake caliper 4 Secondary piston circuit 5 To rear left brake caliper 6 To rear right brake caliper Fit connector on hydraulic pump Clip ABS unit onto bracket Note Do not tighten bolts completely This will make it easier to attach the individual brake lines to the hydraulic unit After tightening brake lines tighten hydraulic unit Remove brake pedal actuator V A G 1869 2 Bleed brake system gt page 110 Code ABS control unit J104 with EDL gt Coding control unit with VAS 505x via Guided Fault Finding function When renewing the control unit select the function Replace for the relevant control unit in the
4. 1 Brakes wear limits page 1 Removing a Note Mark brake pads when removing them if they are to be rein stalled Reinstall in their original position to prevent uneven braking When installing brake discs note direction of travel indicated by arrow on brake disc and fitting location left or right Raise the vehicle Remove wheels 1 Front brakes PR 1LG 41 OD Audi A8 2003 gt Au Brake system Edition 03 2013 Secure brake disc with one wheel bolt see arrow Lever brake pad retaining spring out of brake caliper housing with a screwdriver and remove Unplug connector for brake pad wear indicator Turn connector 90 while using a screwdriver to release con nector from bracket Pull connector upwards out of bracket and detach wire Detach brake line from bracket a gt mson 1 42 Rep gr 46 Brakes mechanism meee Audi A8 2003 gt C 0 Brake system Edition 03 2013 Auer Remove caps 1 Unscrew and remove both guide pins from brake caliper Take off brake caliper housing and lay to one side so that the weight of the brake caliper does not stress or damage the brake hose Take brake pads out of brake caliper housing or from brake carrier Use only methylated spirits to clean the brake caliper housing Installing Check the thickness of the brake disc when renewing the brake pads Refer to wear limit fo
5. 11 Brake carrier Q Bolt to wheel bearing housing Q Bolted onto brake cali per Oh 190 Nm 13 Bolt for bracket O 25Nm 16 Bracket for brake line Q Attach brake line Wc filet y As a t r 446 10143 3 Ceramic front brakes PR 1LW 61 vuy Audi A8 2003 gt Au Brake system Edition 03 2013 Note Do NOT loosen bolts 1 Removing Remove bracket for brake line Loosen and remove the two bolts 10 on the brake carrier Remove brake caliper Leave brake carrier 11 in position on brake caliper Installing Installation is carried out in reverse sequence a Note Take care not to twist brake hose AN Caution Before driving vehicle for the first time make sure function of brakes is OK 3 5 Detaching and attaching front brake disc ceramic brakes AN WARNING The brake disc ring and the brake disc hub are bolted together and must NOT be separated Do NOT slacken the bolted con nection on the brake disc hub Raise vehicle Remove wheels AN Caution On vehicles with ceramic brakes the wheel must not be allowed to drop onto the brake disc This would cause irreparable dam age to the disc Screw two assembly pins from vehicle tool kit into the wheel bolt holes when removing and fitting a wheel Insert the long assembly pin into the top hole Detach brake caliper via bolt 10 gt page 60 Do not l
6. Note On some models the vacuum hose has to be secured at the vac uum pump with a bolt Tightening torque Vacuum pump to cylinder head 9 1 32 Rep gr 47 Brakes hydraulics Audi A8 2003 gt COO Brake system Edition 03 2013 Auer 12 Electric vacuum pump for brakes V192 12 1 Vacuum pump for brakes V192 exploded view 1 Brake servo pressure sen sor G294 Removing and installing gt page 136 2 Vacuum hose Q To brake servo 3 Brake servo relay J569 Q Removing and installing gt Current flow dia grams 4 Non return valve Checking function gt page 136 5 Hose clip QO Renew 6 Clip 7 Stop buffer 8 Vacuum pump for brakes V192 Q Removing and installing gt page 133 Q Checking gt page 134 9 Stop buffer 10 Bracket For correct version refer to gt Electronic parts catalogue ETKA 11 Nut SJA 12 Hexagon bolt 3 12 2 Removing and installing vacuum pump for brakes V192 No provision is made for repairs to vacuum pump for brakes V192 If a fault occurs the vacuum pump for brakes V192 must be renewed 12 Electric vacuum pump for brakes V192 1 33 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 Removing Unplug connector 1 Disconnect vacuum hose 2 from vacuum pump for brakes V192 AN Caution Take care not to damage the vacuum hose The vacuum hose must be renewed i
7. Brake carrier Bolt to wheel bearing housing Bolted onto brake caliper 190 Nm 3 Ceramic front brakes PR 1LW 55 COLD Audi A8 2003 gt Auo _Brake system Edition 03 2013 12 Brake pistons WARNING The brake pistons have different diameters When re installing please make sure that each of the brake pistons is inserted in the correct aperture in the brake cal iper The ceramic inserts on the brake piston act as heat insulators and must not be separated from the brake piston If the ceramic insert is damaged the brake pis tons must be renewed for safety reasons 13 Bolt for bracket Q Tightening torque 25 Nm 14 Brake line connection at brake pipe Q Tightening torque 12 Nm Q Brake hose must not be twisted Note Brake line connection at brake pipe 12 Nm Brake pipe in brake caliper 19 Nm 15 Brake line Q Screw into brake caliper housing Q Screw into brake hose counter hold on brake hose hexagon Q Do not twist hose when fitting Q Ensure that lugs are properly seated in grooves in bracket 16 Bracket for brake line Q Bolt to brake caliper housing Q Attach brake line 17 Brake pipe in brake caliper Q Tightening torque 19 Nm Note Brake pipe in brake caliper 19 Nm Brake line connection at brake pipe 12 Nm 18 Bolt for guide pin Q 30Nm 19 Damper spring Q 2 fitted on each brake caliper Q Detaching and attaching page 57 56 Rep gr
8. Guided Fault Finding To do so use the vehicle diagnostic testing and information sys tem VAS 505x Perform final control diagnosis after attaching brake lines to hydraulic unit gt Guided Fault Finding function of vehicle di agnostic testing and information system VAS 505x Note Final control diagnosis can be used to establish whether line con nections have been interchanged Tightening torques Brake lines to hydraulic unit M10 brake line di 12 ameter 5 mm Brake lines to hydraulic unit M12 brake line di 12 ameter 5 mm Brake lines to hydraulic unit M12 brake line di 20 ameter 8 mm 3 4 Renewing ABS control unit J104 Removing AN Caution The two components must be removed from the vehicle before separating the control unit from the hydraulic unit 28 Rep gr 45 Anti lock brake system Audi A8 2003 gt C 0 Brake system Edition 03 2013 Auer a Note Clean the hydraulic unit carefully before removal Before removing the control unit interrogate the fault memory and print out any fault codes that are displayed Place the hydraulic unit together with the control unit on a clean flat surface Renewal may only be performed by qualified personnel with adequate technical expertise Removing and installing hydraulic unit gt page 24 Slacken bolts 1 and pull control unit 2 off hydraulic unit taking care to keep it straight A46 100
9. When installing a new hydraulic control unit always check the coding gt VAS 505x Vehicle diagnostic testing and information system Always switch off the ignition before carrying out installation or repair work On vehicles with a coded radio find out the anti theft code and disconnect the battery earth strap When working with brake fluid observe the relevant safety precautions and notes gt page 17 Always bleed the brake system using brake filling and bleed ing equipment V A G 1869 or VAS 5234 or similar after all work which involves opening the hydraulic system gt Repair group 47 Additionally perform high pressure and low pres sure tests gt page 83 During the final road test ensure that at least one ABS con trolled braking operation is performed pulsations must be felt at the brake pedal Vehicle diagnostic testing and infor mation system VAS 505x Absolute cleanliness is required when working on the anti lock brake system avoid any products that contain mineral oil such as oil grease etc Thoroughly clean all connections and the adjacent areas be fore loosening but do not use aggressive cleaning agents such as brake cleaner petrol thinners or similar Place removed parts on a clean surface and cover them up Carefully cover or seal open components if repairs are not to be carried out immediately Use sealing plugs from repair kit 1 HO 698 311 A Do not use fluf
10. nstall complete repair kit when servicing Apply a thin coatofassemblypaste G052150A2 tobrake cylinder piston and seal 1 Brake carrier Q Bolt to brake caliper housing 2 Guide pin Q Tightening torque 30 Nm 3 Caps Q Insert into bearing bush 4 Protective cap Q Push onto bleeder valve 5 Bleeder valve Q Tightening torque 15 Nm Q Before screwing in grease thread lightly with lithium grease gt Parts catalogue 6 Bearing bush Q Insert into brake caliper housing 7 Brake caliper 8 Retaining spring Q Note correct installation position Q Engage onto both brake caliper housing studs and onto outer pad re taining spring 9 Protective cap Q Donot damage when in serting piston Q Grease with assembly paste gt Parts catalogue 10 Piston Q Apply a thin coat of assembly paste to piston before inserting Q Allocation gt page 1 11 Seal Q Grease with assembly paste 84 Rep gr 47 Brakes hydraulics Audi A8 2003 gt GNNN Brake system Edition 03 2013 Aue 2 2 Removing and installing piston for front brake caliper Special tools and workshop equipment required Removal wedge VAS 3409 00 0016 Assembly paste gt Parts catalogue Assembly tool for protective caps T10146 5 T10146 ge Piston resetting appliance T10145 Removing Force piston out of brake caliper housing using compressed air a Note Place
11. the brake caliper Q Always renew on both sides of axle Q Allocation gt page 1 Brakes Q Removing and installing any y m JAN A E a N ee na 3 Ban 54 Rep gr 46 Brakes mechanism 46 10143 ASEE Audi A8 2003 gt 44 Brake system Edition 03 2013 Auer page 57 5 Brake pads Note Ouovoo O O m OOO OOOD A wire for the wear indicator is fitted to the inner pad There is an adhesive foil on the backplates of the outer brake pads Remove the protective foil before fitting pads Before fitting pads clean guide surfaces and apply a thin coating of polycarbamide grease gt Parts catalogue Different versions available gt Parts catalogue Always renew on both sides of axle Removing and installing gt page 57 Checking pad thickness gt Maintenance Booklet 4E Locating bolt Tightening torque 5 Nm Brake disc Wear limit gt page 1 Always renew on both sides of axle Detach brake caliper prior to removing Lightly grease contact surfaces between brake disc and wheel hub with polycarbamide grease G 052 142 A2 Allocation of brake discs gt page 1 Removing and installing gt page 62 Renewing gt page 63 8 Splash plate 9 Bolts for splash plate Q Tightening torque 9 Nm 10 Bolts Note Loosen these bolts to remove brake caliper a Note 11 m w m m Always renew if removed 190 Nm
12. 1 Bleeding sequence for vehicles with Electronic Stabilisation Program ESP Applies to steel and ceramic brakes Unlike ESP 5 3 ESP 5 7 does not incorporate hydraulic pump V156 It is therefore not necessary to bleed the pre charging pump with the diagnostic tester Note A pressure of at least 2barisrequired forbleeding the hy draulic unit For this reason it is trportant to always check the pressure setting on the bleeder unit Only use the brake pedal actuator when installing brake sys tem components and bleed the system afterwards Special tools and workshop equipment required 1 1 0 Rep gr 47 Brakes hydraulics Audi A8 2003 gt GNNN Brake system Edition 03 2013 Aue VAS 5234 Brake filling and bleeding equipment VAS 5234 woo 1104 or Brake filling and bleeding equipment V A G 1869 with up grade kit and extraction unit V A G 1869 4 or V A G 1869 Brake filling and bleeding equipment without up grade kit and extraction unit V A G 1869 4 Bleeding brake system using brake filling and bleeding equipment V A G 1869 or VAS 5234 Observe instruction manual for VAS 5234 or for V A G 1869 Connect V A G 1869 or VAS 5234 Open bleeder screws in the specified order and bleed brake calipers assist as required with pedal pressure Bleed sequence for LHD and RHD vehicles 1 Front left side brake caliper 2 Front right side brake caliper 3 Re
13. 46 Brakes mechanism Audi A8 2003 gt CCGG Brake system Edition 03 2013 Auer 3 2 Detaching and attaching damper spring Detaching First disengage damper springs A left and right from guide pin B using commercially available pliers Then pull damper springs A out of brake pads C Attaching First engage damper springs A left and right in bottom hole in corresponding brake pads C Then engage damper springs A left and right in guide pin B using commercially available pliers AN Caution Make sure that the damper springs are fitted correctly at the guide pin and brake pads Installation position of damper springs at guide pin and brake pads arrows 3 3 Removing and installing brake pads ce ramic brakes Removing l Note The brake caliper does not have to be detached in order to remove the brake pads Mark brak pads when removing MEM if they ar tobe rein Stalled Reinstall in their original position to prevent uneven braking The ceramic brake discs must always be checked for damage and wear when renewing the brake pads gt 2 Assessment of ceramic brake discs page 4 3 Ceramic front brakes PR 1LW 57 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 3 Assessing degree of wear on ceramic brake discs page 7 Raise the vehicle Remove wheels A
14. 5 km h Otherwise the EDL control can activate the brakes if the rollers start at different points in time All brake test equipment approved by Audi meets these require ments 4 3 Vehicles with four wheel drive Testing on a single axle brake dynamometer for four wheel drive vehicles The rollers drive the wheels of one axle in opposite directions to avoid transmitting torque to the other axle Test speed must not exceed 6 km h Otherwise the EDL control can activate the brakes if the rollers start at different points in time AN WARNING The Torsen differential will be seriously damaged if test speed exceeds 6 km h All brake test equipment approved by Audi meets these require ments Testing on a single axle brake dynamometer Test speed must not exceed 6 km h Otherwise the EDL control can activate the brakes if the rollers start at different points in time All brake test equipment approved by Audi meets these require ments 4 4 EPB Electronic Parking Brake on brake dynamometer Test sequence Drive rear wheels of vehicle onto test rollers do not switch off ignition As soon as the rollers reach a speed in excess of 3 km h the TUV mode TUV German technical inspection agency is activated 4 Brake test 1 5 yy Audi A8 2003 gt Auo _ Brake system Edition 03 2013 The instrument cluster will then display a crossed out yellow symbol of the electronic parking brake gt Owner
15. Thoroughly blow out the brake discs with compressed air in cluding the area between the cooling channels and ventilation arillings 3 Assessing degree of wear on ceramic brake discs 1 3 yy Audi A8 2003 gt Auo _ Brake system Edition 03 2013 Carefully place the clean brake disc on the scales The disc must be renewed when the weight of the disc is less than or equal to the indicated minimum weight Always renew brake discs on both sides of the axle Always renew brake discs on both sides of axle if the brake discs have to be renewed because of wear there has been a technical modification to the replacement brake disc indicated by changed part number In this case always renew the brake discs on both sides of the axle When doing so always renew the brake pads on both sides of the axle 1 4 Rep gr 00 Technical data eee Audi A8 2003 gt 44 Brake system Edition 03 2013 Aue 4 Brake test 4 1 General notes The wheels are driven by the brake test rollers During the test the gearbox must be in neutral on manual gear boxes or in position N on automatic gearboxes Follow the instructions provided by the manufacturer of the brake test equipment when performing the test Note Electronic brake control systems are inoperative when the ignition is switched off 4 2 Vehicles with front wheel drive Perform brake test on a single axle brake dynamometer Test speed must not exceed
16. brake pressure sender G 201 Insert brake pedal actuator V A G 1869 2 between brake pedal and driver s seat Depress the brake pedal at least 60 mm Connect hose of bleeder bottle to bleeder screws of front left and rear left brake calipers and open bleeder screws Note This will release the pressure in the hydraulic unit Close front left and rear left bleeder screws Do not remove brake pedal actuator V A G 1869 2 As protection against escaping brake fluid place a sufficient number of lint free cloths in area beneath control unit and hy draulic unit Mark brake lines 26 Rep gr 45 Anti lock brake system Audi A8 2003 gt GNNN Brake system Edition 03 2013 Auer Disconnect brake lines from hydraulic unit to brake master cylinder 3 and tie up Disconnect remaining brake lines 2 on hydraulic unit AN WARNING Do not bend the brake lines in the vicinity of the hydraulic unit Seal brake lines and tapped holes with sealing plugs from re pair kit Release control unit connector arrow and unplug a Note Make sure brake fluid does not get into connector housing of control unit This can result in corrosion of the contacts and failure of the system Use compressed air to carefully clean connector housing if necessary Release retaining clip on both sides from below 1 Remove retaining clips in direction indicated arrow
17. carried out in reverse sequence Bleed brake system gt page 110 Perform ESP road test gt vehicle diagnostic testing and in formation system VAS 505x in the function Guided Fault Finding 5 Removing and installing parts of ESP system 37 GANN Audi A8 2003 gt Aue Brake system Edition 03 2013 46 Brakes mechanism 1 Front brakes PR 1LG gt 1 1 Servicing front brakes page 38 1 1 Servicing front brakes gt 1 2 Removing and installing brake pads page 41 gt 1 3 Renewing brake caliper page 45 Note Always install all parts supplied in repair kit After renewing brake pads depress brake pedal firmly several times with vehicle stationary so that the pads are properly seated in their normal operating position To draw off brake fluid from brake fluid reservoir use a bleeder bottle which is used only for brake fluid Brake fluid is poison ous and must NOT be drawn off by sucking through a hose Check that the brake caliper moves freely by moving it from side to side 38 Rep gr 46 Brakes mechanism pe Audi A8 2003 gt CCGG Brake system Edition 03 2013 Auer 1 Brake pads a Note Q There is an adhesive foil on the backplates of the outer brake pads Re move the protective foil before fitting pads QO Before fitting pads clean guide surfaces and apply a thin coating of polycarbamide grease gt Parts cata logue Q D
18. correctly in the pad retainers arrows Secure brake caliper housing with new self locking bolts Note The repair kit includes four self locking hexagon bolts which must always be installed Fit connector for electronic parking brake in retainer 4 Rear brakes electronic parking brake and handbrake EPB T 1 Y Audi A8 2003 gt Au Brake system Edition 03 2013 Display on VAS 505x Request to enter a display group in display zone 1 Display zone 2 shows a keypad Enter 06 or 006 as display group number via the keypad 2 and confirm entry with Q key moves piston to original position Press left button to exit from basic setting mode When installing new brake pads Display on VAS 505x The prompt to enter a display group appears in display zone Display zone 2 shows a keypad Press left arrow button twice Display on VAS 505x Select function 10 Adaption Measure the thickness of the thinner of the two brake pads without backplate and enter the value via the keypad or scroll bar Select keypad or enter via scroll bar Enter value between 10 23 mm via keypad 2 Confirm by pressing 9 key moves piston to original position Select Save and then Accept When re installing old brake pads different procedure 72 Rep gr 46 Brakes mechanism Audi A8 2003 g
19. in cluding backplate TE ae mm mm 22 Brake disc wear limit___ mm 20 inte NEVE 2 Special security vehicle gt 4 Rear brakes electronic parking brake and handbrake EPB page 65 u Note When performing repair workon brakes hairline cracks are often found on the friction suitface of the brake discs Hairliri cracks up to a length of 10 mm do not present a technical problem and do not justify a renewal of brake discs Brake discs with cracks going all the way across the friction surface must be renewed gt page 54 Brake caliper caliper TRWCII45HE DK Cll45 HE DK No 2 Rep gr 00 Technical data See eae Audi A8 2003 gt C 0 Brake system Edition 03 2013 Auer Ceramic rear brakes Ventilated brake mm 356 disc Brake disc thick mm 28 ness Brake disc wear The minimum thickness of the limit brake disc is stamped onto the brake disc hub as a wear limit specification Brake caliper 1 piston Minimum pad thickness includ ing backplate and damper plate gt 4 Rear brakes electronic parking brake and handbrake EPB page 65 a Note Depending on the version the minimum weight of the brake disc is stamped on the disc The brake disc must then be additionally weighed in order to assess the amount of wear The disc must be renewed when the minimum weight is reached Brake discs should always be renewed on both sides
20. installing pistons for front brake caliper Special tools and workshop equipment required Removal wedge 3409 Piston resetting appliance T10145 5 Brake caliper ceramic brakes 97 WO Audi A8 2003 gt Au Brake system Edition 03 2013 Lithium grease G 052 150 A2 Removing Force pistons out of brake caliper housing one at a time using compressed air The pistons can only be removed one at a time Hold the opposite piston in the caliper housing with piston resetting appliance a Use blocks of wood or similar b to keep the other pistons in place Also place a piece of wood c against the resetting tool to prevent the piston from being damaged when it is forced out Remove seal using removal wedge 3409 When removing ensure that the bore of the cylinder is not dam aged Installing AN WARNING The brake pistons have different diameters When re installing please make sure that each of the brake pistons is inserted in the correct aperture in the brake caliper The ceramic inserts on the brake piston act as heat insulators and must not be separated from the brake piston If the ceramic insert is dam aged the brake pistons must be renewed for safety reasons The surface of the piston and seal should be cleaned using only methylated spirits and then dried Apply a thin coat of lithium grease G 052 150 A2 to piston and seal before inserting Insert the seal into
21. interior Remove brake light switch gt page 34 First press brake pedal in direction of brake servo and hold 1 Brake pedal 2 Push rod 3 Retaining lugs Insert special tool T10159 and pull in direction of driver seat When doing this counter hold on brake pedal At this moment the pedal must not be allowed to move backwards This will press the retaining lugs 3 of the mounting off the ball head of the push rod 2 For illustration purposes the method of separating the brake ped al from the brake servo is shown with the pedal cluster removed Attaching brake pedal to brake servo Hold ball head of push rod in front of mounting and push brake pedal in direction of brake servo so that the ball head audibly locks into place Remaining installation steps are carried out in reverse sequence Adjust brake light switch gt page 34 AN Caution Before driving vehicle for the first time make sure function of brakes is OK Pou Audi A8 2003 gt 44y 1 CL e mma a N46 0368 5 Brake pedal LHD exploded view 15 COLD Audi A8 2003 gt Auo _Brake system Edition 03 2013 5 2 Removing and installing brake pedal LHD vehicles Removing Remove driver s footwell cover gt Rep gr 68 General body repairs interior Remove brake light switch gt page 34 Separate brake pedal from brake servo page 74 Unscrew hexagon bolt Remov
22. is too large or too small The values can be entered via the keypad as well 6 Rear brake calipers for electronic parking brake and handbrake EPB 1 07 Y Audi A8 2003 gt Au Brake system Edition 03 2013 Press key 4 to enter values via keypad Display on VAS 505x Request in display zone 1 Enter adaption value 0 65535 Display zone 2 shows a keypad Enter the measured pad thickness in display zone 2 via the keypad and confirm entry with 9 key Display on VAS 505x Zone 3 displays the newly entered pad thicknessivalue indi lt cated by the sliding bar Store the new pad thickness by pressing key 5 1 08 Rep gr 47 Brakes hydraulics Audi A8 2003 gt GNNN Brake system Edition 03 2013 Auer Display on VAS 505x Store channel 6 appears in display zone 1 Zone 2 displays the specified limits for brake pad thickness Zone 3 displays the original and the newly entered pad thick ness value Confirm and store the new pad thickness by pressing key Display zone 1 indicates Store channel 6 Value 0 23 stor ed End self diagnosis and switch ignition off Fit wheels gt ELSA Wheel Tyre Guide gt Rep gr 44 Check brake fluid level and top up if necessary AN Caution Before driving vehicle for the first time make sure function of brakes is OK 6 Rear brake calipers f
23. lechnical problem on the ceramic brake discs 2 3 Cracks in area of bolted connection on ceramic brake discs Checking area of bolted connection on friction ring and brake disc hub AN WARNING The brake disc ring and the brake disc hub are bolted together and must NOT be separated Do NOT slacken the bolted con nection on the brake disc hub Ceramic brake discs must be renewed if there are cracks in the area of the bolted connection of the brake disc hub extending into the friction surface of the brake disc arrows gt page 54 The brake discs must be renewed on both sides of the axle if renewal is necessary because of brake disc wear there has been a technical modification to the replacement brake disc indicated by changed part number Always renew brake discs on both sides of axle gt page 63 When doing so always renew the brake pads on both sides of the axle gt page 57 2 Assessment of ceramic brake discs 5 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 2 4 Edge fractures Edge fractures arrow are caused by mechanical damage to the edges Permissible max width depth 2 mm max length 10 mm max 3 edge fractures per brake disc If any of the criteria listed above are exceeded the brake disc must be renewed gt page 54 Always renew brake discs on both sides of axle if J renewal is necessary because of b
24. m Tightening torque 19 Nm P Brake pipe in brake caliper 19 Nm Brake line connection at brake pipe 12 Nm 2 Front brakes PR 1LJ 1LL 1LM 1LK 47 CO Audi A8 2003 gt Au Brake system Edition 03 2013 12 Bracket Q Bolt to brake caliper housing Q Attach brake line 13 Bolt for bracket Q Tightening torque 25 Nm 14 Brake caliper If assembly work is required do not leave caliper hanging from brake hose but secure it to body with wire With the exception of Renewing brake pads gt page 48 and Servicing front brake caliper gt page 88 no repairs may be performed on the brake caliper Do not twist hose when installing Allocation gt page 1 Brakes gt 2 3 Renewing brake caliper page 52 Ooo O oO 15 Retaining spring Q Note correct installation position Note The retaining spring must be push ed under the brake carrier after en gaging onto both studs If incorrectly installed the wear of the outer pad cannot be adjusted and the pedal travel will be increased as a result 2 2 Removing and installing brake pads Check the thickness of the brake diseewhenirenewing the brake pads Refer to wear limit for brak disc We ardtimit gt 1 Brakes wear limits page 1 Removing Note Mark brake pads when removing them if they are to be rein Stalled Reinstall in their original position to prevent uneven braking When insta
25. of the axle a Note Hairline cracks on the friction surfaces of ceramic brakes can be caused during manufacturing and therefore already appear to varying degrees when the brakes are new Hairline cracks on the friction surfaces do not justify a renewal of the ceramic brake discs 1 Brakes wear limits 3 COED Audi A8 2003 gt Au Brake system Edition 03 2013 2 Assessment of ceramic brake discs 1 Cooling channel lands 2 Friction layer 3 Carrier material IEF 395 Ad0 103455 2 1 Visible features of ceramic brake discs Checking area of bolted connection on friction ring and brake disc hub AN WARNING The brake disc ring and the brake disc hub are bolted together and must NOT be separated Do NOT slacken the bolted con nection on the brake disc hub 4 Rep gr 00 Technical data Audi A8 2003 gt COO Brake system Edition 03 2013 Auer Due to the production process there already are relaxation cracks varying degrees on the friction surface of the brake disc when it is new a Note Relaxation cracks on a ceramic brake disc do not constitute a technical problem The relaxation cracks may be clearly visible and vary in size 2 2 Superficial cracks in cooling channel lands Superficial cracks in the cooling channel lands arrow are caused during manufacturing a Note Superficial cracks in the cooling channel lands do not constitute a
26. onto hydraulic unit s A Q Tightening torque 20 gt SSL Nm om 10 Q Removing and installing eT gt page 36 i 9 ABS hydraulic unit N55 A45 0182 with ABS control unit with EDL J104 Q Removing and installing gt page 24 10 Nut with washer Q Tightening torque 9 Nm 11 Bracket for ESP 12 Retaining clip 3 3 Removing and installing hydraulic con trol unit Special tools and workshop equipment required 24 Rep gr 45 Anti lock brake system Audi A8 2003 gt GNNN Brake system Edition 03 2013 Aue Torque wrench V A G 1331 V A G 1331 Brakespedabactuatores VsArGit869 2 Sealing plugs repair kit part No 1HO 698 311A V A G 1869 2 Fitting location The hydraulic control unit is fitted on the left hand side of the en gine compartment Removing AN WARNING Do not bend the brake lines f N45 0078 Switch off ignition Remove hexagon bolts 1 securing coolant expansion tank 3 Electronic stabilisation program Bosch 5 7 25 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 Remove hexagon bolts 1 Unplug connector from coolant expansion tank Move coolant expansion tank clear to one side Yop 7 if i ie fi i git l f l p f j Jj E Remove hexagon bolt 1 securing fluid reservoir and pull fluid reservoir to the side and out of buffer Unplug connector 1 from
27. push rod in front of mounting and push brake pedal in direction of brake servo so that the ball head audibly locks into place gt page 75 Adjust brake light switch brake pedal switch gt page 34 Bleed brake system gt page 110 AN Caution Before driving vehicle for the first time make sure function of brakes is OK 6 Removing and installing mounting bracket TT COLD Audi A8 2003 gt Au Brake system Edition 03 2013 7 Overview of components electronic parking brake and handbrake EPB 1 Parking brake switch Q Pull switch to apply brake Q Push switch to re lease brake Q Fitting location in centre console Q Removing and installing gt page 36 2 LED indicator for applied parking brake light emitting diode 3 EPB system fault warning lamp yellow 4 Indication of achieved clamping force and dynamic deceleration 5 Electronic parking brake with rear left actuator motor Q Removing and installing gt page 100 Q Removing and installing control unit for electron ic parking brake and handbrake gt page 79 Removing and installing actuator motor for elec tronic parking brake and handbrake gt page 79 6 EPB control unit Q Control unit for electro mechanical parking brake EPB J540 Q Fitting location below battery in rear right side panel Q Removing and installing gt page 79 7 Electronic parking brake with rear left actuator
28. s Manual Instruments and warning indicator lamps The EPB will now function as follows The full brake force is not applied at once but step by step each time the parking brake switch is operated The brake will be fully applied after operating the button 3 times The brake is released by pressing the switch once Requirements for T V mode Ignition on Front wheels speed 0 km h Rear wheels min speed 3 km h max Speed 9 km h AN WARNING When testing models with four wheel drive you must use brake test rollers with synchronised wheel speeds 1 6 Rep gr 00 Technical data 5 Brake fluid 5 1 General notes Brake fluid is hygroscopic i e it has the tendency to absorb water and moisture from the atmosphere The boiling point decreases as the water content increases which means a considerable rise in brake fluid temperature can lead to formation of vapour bubbles and brake failure The colour of the brake fluid becomes darker over the course of time A dark brake fluid colour is not an indication of its condition The change in colour is caused by chemical reactions and may occur within a short period several weeks particularly in vehi cles equipped with ABS AN WARNING Rubber parts of brake system sleeves seals are not com patible with mineral oil fuel and cleaning agents Even minute quantities coming into contact with a seal or sleeve will affect the component and coul
29. socket head bolts are tightened otherwise the flanged connection on the brake line will not be formed correctly Clamp brake line in flanging tool tightly enough to prevent it from moving Then fold up limit stop A and fully tighten socket head bolts in diagonal sequence using Allen key C N47 10061 14 Repairing brake lines 1 41 ANP Audi A8 2003 gt Aue Brake system Edition 03 2013 Screw spindle into flanging tool onto limit stop Unscrew spindle Slacken off socket head bolts in diagonal sequence Take brake line out of flanging tool Clean and inspect brake line with flanged connection Briefly flush out section of pipe remaining in vehicle Connect brake filling and bleeding equipment VAS 5234 fit hose of bleeder bottle onto flared connection on brake line and operate brake filling and bleeding equipment VAS 5234 briefly until a small quantity of brake fluid has run through Blow out new section of brake line with compressed air before installing Join together sections of brake line with connecting piece Install brake line Then bleed brake system gt page 110 A Caution Before driving vehicle for the first time make sure function of brakes is OK 1 42 Rep gr 47 Brakes hydraulics
30. with a brake vacuum pump Checking function With the engine switched off firmly depress the brake pedal several times this reduces the vacuum present in the servo unit Then hold brake pedal in applied position employing moderate force and start engine If the servo unit is working properly the pedal will give slightly under foot servo assistance becomes activated Renew complete unit if defective With bonded gasket Q Removing and installing gt page 117 10 Seal Q Renew Ov O OD OU 11 Brake line Q Tightening torque 24 Nm Q Brake master cylinder primary piston circuit to hydraulic unit 12 Trunnion bolt Q Tightening torque 10 Nm 13 Brake line Q Tightening torque 24 Nm Q Brake master cylinder secondary piston circuit to hydraulic unit 14 Mounting bracket for pedal cluster Q Removing and installing gt page 77 15 Hexagon nut QpeTighteningtorquen25Nm 16 Torx socket head bolt T45 Q Tightening torque 25 Nm Adjusting ball head LHD vehicles a 184 4 mm 0 5 mm a Note Surface 1 for measuring When measuring the ball head it must be set at right angles to the surface of the brake servo Measure to end of ball head without gasket fitted Tightening torque Ball head to brake servo 30 Nm AN Caution Before driving vehicle for the first time make sure function of brakes is OK 8 Brake servo brake master cylinder exploded view 1 1 3 COLD Audi A
31. with cracks going all the way across the friction surface must be renewed Ceramic front brakes Brake caliper Nd Brembo M6 Al Factory code PR 1LW No Ventilated brake mm 380 disc Brake disc thick mm 38 ness Brake disc wear The minimum thickness of the limit brake disc is Stamped onto the brake disc hub as a wear limit specification Brake caliper 6 mm 2 x 32 36 38 piston monoblock 1 Brakes wear limits 1 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 ____Ceramicfrontbrakes__ front brakes Minimum pad pad 9 5 thickness includ ing backplate and damper plate 54 gt 3 Ceramic front brakes PR 1LW page Note Depending on the version the minimum weight of the brake disc is stamped on the disc The brake disc must then be additionally weighed in order to assess the amount of wear The disc must be renewed when the minimum weight is reached Brake discs should always be renewed on both sides of the axle Note Hairline cracks on the friction surfaces of ceramic brakes can be caused during manufacturing and therefore already appear to varying degrees when the brakes are new Hairline cracks on the friction surfaces do not justify a renewal of the ceramic brake discs Factory code PR No Ventilated brake disc Brake slas mnIGRNESS akw Yas 4Kz 18 17 310 Brake sne piston Brake pad thickness Brake pad wear limit
32. 003 gt Au Brake system Edition 03 2013 Fit actuator motor as shown in illustration item 1 Note Ensure that seal is fitted correctly Then turn actuator motor in such a way item 2 that bolt hole a and thread in brake caliper housing b are aligned Make sure that actuator motor is flush with brake housing Fit both securing bolts on actuator motor Tightening torque 12 Nm Important Bolts must be fitted and screwed in several turns by hand If the thread is damaged the complete brake caliper has to be renewed Push actuator motor connector into bracket a Note To avoid any damage to connector only fit it by hand Insert connector on vehicle side of connection Fit wheels gt ELSA Wheel Tyre Guide After renewing actuator motor you must use vehicle diagnostic tester to perform basic setting 10 in EPB function To do so use the vehicle diagnostic testing and information sys tem VAS 505x Either select basic setting 10 gt page 20 under Function or under Running gear repair group 01 34 65 Brake system repair group 01 45 46 01 Self diagnosis compatible systems 53 Parking brake J540 Control unit for electromechanical parking brake J540 Basic setting 3 Function test electronic parking brake and handbrake AN Caution Before driving vehicle for the first time make sure function of brakes is OK 82 R
33. 45 Clean sealing surface 2 using a plastic scraper 1 Check valves 3 for damage A WARNING Sealing surface of hydraulic unit must be clean and flat The hydraulic unit must be renewed if the sealing surface or the contact pins are damaged The seal on the control unit cannot be replaced A46 10046 The seal on the control unit must not be lifted or pulled out Note Use the cleaning agent provided do not use any aggressive cleaning products Check sealing surface for damage visual inspection Assembling AN Caution Make sure that no moisture or dirt gets inside the control unit Do not blow out control unit or hydraulic unit with compressed air Severe shocks or jolts can damage the control unit The control unit must not be re installed if it has been damaged in any way 3 Electronic stabilisation program Bosch 5 7 29 0 Audi A8 2003 gt Aue Brake system Edition 03 2013 With solenoids pointing downwards carefully press on control unit 1 guiding it over valves on hydraulic unit 2 Make sure that valves remain straight The edge of the control unit housing must slide over the shoul der on the hydraulic unit Note Use new bolts To avoid any risk of leakage at the flexible seals a new control unit must not be fitted more than twice onto an old hydraulic unit that is being re installed A control unit which has bee
34. 47 3 1 3 2 3 3 3 4 3 5 3 6 4 4 1 4 2 5 5 1 5 2 6 6 1 7 7 1 7 2 1 1 1 1 2 2 2 1 2 2 3 3 1 3 2 4 4 1 4 2 5 5 1 5 2 6 6 1 6 2 7 7 1 7 2 8 9 9 1 10 10 1 11 11 1 11 2 11 3 11 4 11 5 11 6 11 7 Contents Servicing ceramic brakes 00000 a a a a a eee eee Detaching and attaching damper spring 0 e eee eae Removing and installing brake pads ceramic brakes 000000 eee eee Removing and installing brake caliper ceramic brakes 000200000 Detaching and attaching front brake disc ceramic brakes 00000 000 Renewing front brake disc ceramic brakes 00000 ee Rear brakes electronic parking brake and handbrake EPB 0000000 Servicing rear brakes all models including ceramic brakes 0 00 00 ee Removing and installing brake pads rear brakes 20 00 cee eee ee Brake pedal LHD exploded View 0 0 ccc ccc ee eee nes Separating brake pedal from brake servo 0000 e eee ee eee Removing and installing brake pedal LHD vehicles 2000002005 Removing and installing mounting bracket 0 0 0 0 cece eee eens Removing and installing mounting bracket 0 0 eee eee Overview of components electronic parking brake and handbrake EPB Removing and installing control unit for electronic parking brake and handbrake
35. 5 Checking non return valve The valve should allow air to pass in the direction indicated by the arrow Valve must remain closed in opposite direction Observe correct installation position Arrow must point towards vacuum pump 1 36 Rep gr 47 Brakes hydraulics Audi A8 2003 gt GANNI Brake system Edition 03 2013 Aue 13 Brake hoses and brake lines 13 1 Routing of brake hoses lines Replacement brake hoses and brake lines are supplied as spare parts ready to be installed Secure brake hoses and brake pipes to the original mounting points when installing Brake lines to hydraulic unit Item 1 Hexagon bolt M10 and M12 5 mm brake lines 12 Nm tightening torque Item 2 Hexagon bolt M14 8 mm brake lines 12 Nm tightening torque Brake line routing at front wheels Item 1 Hexagon bolt tightening torque 25 Nm Item 2 Brake hose bracket Item 3 Retaining spring Item 4 Brake line 14 Nm tightening torque Item 5 Brake hose make sure that locating lugs engage properly in bracket Routing of brake lines at rear wheels A47 0177 13 Brake hoses and brake lines 1 37 C amp D Audi A8 2003 gt Au Brake system Edition 03 2013 Item 1 Brake line 14 Nm tightening torque Item 2 Hexagon bolt tightening torque 10 Nm Item 3 Retaining spring ltem 4 Brake hose bracket Item 4 Brake line t4 Nm tightening to
36. 8 2003 gt Auo _ Brake system Edition 03 2013 9 Removing and installing brake mas ter cylinder 9 1 Removing and installing brake master cylinder Special tools and workshop equipment required Brake filling and bleeding equipment VAS 5234 woo 1104 or Brake filling and bleeding equipment V A G 1869 A Sealing plugs repair kit part No 1HO 698 311A Removing Detach plenum chamber cover Drawing off brake fluid with brake filling and bleeding equipment V A G 1869 or VAS 5234 Open brake fluid reservoir As protection against escaping brake fluid place a sufficient number of lint free cloths in area beneath brake master cylin der Y 447 0137 1 1 4 Rep gr 47 Brakes hydraulics _ w Audi A8 2003 gt COG Brake system Edition 03 2013 Auer Draw off as much brake fluid as possible from brake fluid res ervoir using brake filling and bleeding equipment VAS 5234 or extraction unit V A G 1869 4 Unplug connector from sender for float warning indicator 1 Removing body brace Remove bolts with washers 1 tightening torque 45 Nm Remove bolts with washers 2 tightening torque 3 Nm ltem 3 Front section of plenum chamber ltem 4 Suspension turret Arrow in illustration points in direction of travel Remove bolts with washers 1 tightening torque 9 Nm ltem 2 Cross piece for suspension turret ltem 3 Windscr
37. N Caution On vehicles with ceramic brakes the wheel must not be allowed to drop onto the brake disc This would cause irreparable dam age to the disc Screw two assembly pins from vehicle tool kit into the wheel bolt holes when removing and fitting a wheel Insert the long assembly pin into the top hole Secure brake disc with one wheel bolt Unplug connector for brake pad wear indicator as shown in illustration Turn connector 90 while using a screwdriver to release con nector from bracket Pull connector upwards out of bracket and detach wire a Note The brake caliper does not have to be detached in order to re move the brake pads First disengage damper springs A left and right from guide pin B using commercially available pliers Then pull damper springs A out of brake pads C Remove bolt for guide pin B Pull guide pin out of brake pads and brake caliper AN WARNING Retaining spring is under tension and could cause injury when pulling out the guide pin if suitable precautions are not taken i A46 10144 58 Rep gr 46 Brakes mechanism Audi A8 2003 gt C 0 Brake system Edition 03 2013 Auer Disengage pad wear indicator wire from retaining spring 2 a Note Before removing old brake pads press pistons back into cylinders with resetting appliance Before pressing the pistons back draw off brake f
38. Service Workshop Manual Audi A8 2003 gt Brake system Edition 03 2013 Service Department Technical Information Service List of Workshop Manual Repair GroupsList of Workshop Manual Repair GroupsList of Workshop Manual Repair Groups Repair Group 00 Technical data 45 Anti lock brake system 46 Brakes mechanism 47 Brakes hydraulics Technical information should always be available to the foremen and mechanics because their careful and constant adherence to the instructions is essential to ensure vehicle road worthiness and safety In addition the normal basic safety precautions for working on motor vehicles must as a matter of course be observed All rights reserved No reproduction without prior agreement from publisher Copyright 2013 Audi AG Ingolstadt A0051005420 Audi A8 2003 gt Brake system Edition 03 2013 Aue Contents OO Technicaldata x1 exiled eae eet eh eee eects Shas a ate a 1 1 Brakes wearlimitS 323 2222 24 228 stvece sto ebge ieee Satu hee eee Oe ee 1 2 Assessment of ceramic brake discs 0 ccc eens 4 2 1 Visible features of ceramic brake discs 0 00 ccc eee 4 2 2 Superficial cracks in cooling channel lands 0 0 0 ee ee 5 2 3 Cracks in area of bolted connection on ceramic brake discs 0 0005 5 2 4 Edge fractures iae nacad diaa ale gee hana APS Bebe od oh aa acs od aAa a 4a aa e gal ad 6 2 5 Chipping on ceramic brake disc
39. The retaining spring must be pushed under the brake carrier after engaging onto both studs If incorrectly installed the wear of the outer pad cannot be adjusted and the pedal travel will be in creased as a result AN Caution After installing the brake pads and before driving the vehicle depress brake pedal firmly several times with the vehicle sta tionary so that the brake pads are properly seated in their normal operating position Check brake fluid level and top up if necessary AN Caution Before driving vehicle for the first time make sure function of brakes is OK 2 3 Renewing brake caliper Removing Note Mark brake pads when removing them if they are to be rein stalled Reinstall in their original position to prevent uneven braking Raise the vehicle Remove wheels 52 Rep gr 46 Brakes mechanism meee Audi A8 2003 gt C 0 Brake system Edition 03 2013 Auer Secure brake disc with one wheel bolt see arrow Remove brake pads gt page 48 Installing Install brake pads gt page 48 Bleed brake system gt page 110 Fit wheels gt ELSA Wheel Tyre Guide gt Rep gr 44 AN Caution Affer installing the brake pads and before driving the vehicle depress brake pedal firmly several times with the vehicle sta tionary so that the brake pads are properly seated in their normal operating position Check brake
40. a piece of wood in the recess to prevent damaging the pis ton ear 2 Brake calipers FNR G60 85 WO Audi A8 2003 gt Au Brake system Edition 03 2013 Take out seal Todo this use removal wedge 3409 Note When removing ensure that the bore of the cylinder is not dam aged Installing The surface of the piston and seal should be cleaned using e SS ros only methylated spirits and then dried Apply a small amount of assembly paste to piston and seal before inserting Insert inner seal in groove in brake caliper housing with re moval wedge 3409 Press in protective cap with special tool 1 and 2 Item 1 Assembly tool for protective caps T10146 1 Item 2 Piston resetting appliance T10145 Use jaw protectors Push protective cap onto brake caliper housing and press it in so that it is seated flush arrow Atthis stage it should not be possible to remove the protective cap from the brake caliper housing by hand Apply a small amount of assembly paste to piston and seal before inserting A47 0151 86 Rep gr 47 Brakes hydraulics eee Audi A8 2003 gt 444 Brake system Edition 03 2013 Auer Lift up piston with standard extension and ratchet attachment as shown in illustration and press lightly onto protective cap Keep the piston straight to avoid damaging the protective cap Inflate protective cap with c
41. ake fluid level and top up if necessary AN Caution Before driving vehicle for the first time make sure function of brakes is OK 1 Front brakes PR 1LG 45 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 2 Front brakes PR 1LJ 1LL 1LM 1LK gt 2 1 Servicing front brakes page 46 2 1 Servicing front brakes gt 2 2 Removing and installing brake pads page 48 gt 2 3 Renewing brake caliper page 52 Note Always install all parts supplied in repair kit After renewing brake pads depress brake pedal firmly several times with vehicle stationary so that the pads are properly seated in their normal operating position To draw off brake fluid from brake fluid reservoir use a bleeder bottle which is used only for brake fluid Brake fluid is poison ous and must NOT be drawn off by sucking through a hose Check that the brake caliper moves freely by moving it from side to side 1 Brake pads Note S gt D gt 3 Y Q gt u Q There is an adhesive foil on the backplates of the outer brake pads Re move the protective foil before fitting pads QO Before fitting pads clean guide surfaces and apply a thin coating of polycarbamide grease Parts cata logue Q Different versions avail able gt Parts catalogue Q Always renew on both sides of axle Q gt 2 2 Removing and in stalling brake pads page 48 Q Che
42. ar left side brake caliper 4 Rear right side brake caliper Keep bleeding the calipers until clear foam free brake fluid emerges Close bleeder screw AN Caution Before driving vehicle for the first time make sure function of brakes is OK 7 2 Changing brake fluid Changing brake fluid gt Maintenance Booklet 4E Work descriptions Changing brake fluid every 2 years 7 Bleeding brake system 1 1 1 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 8 Brake servo brake master cylinder exploded view Note Use only new brake fluid Observe information on brake fluid res ervoir 1 Torx bolt T45 QO Tightening torque 23 Nm 2 Self locking hexagon nut Q Tightening torque 49 Nm 3 Tandem brake master cyl inder Q Cannot be repaired If faulty renew complete Q Removing and installing gt page 114 4 Sealing plug Moisten with brake fluid and press into brake flu id reservoir 5 Filler cap 6 Brake fluid reservoir 7 Vacuum hose Insert into brake servo unit 8 Sealing plug LJ Connection for vacuum hose 9 Tandem brake servo Q Adjusting ball head gt page 113 Q On petrol engines the vacuum required is tak en from the intake mani 1 1 2 Rep gr 47 Brakes hydraulics pe Audi A8 2003 gt 44 Brake system Edition 03 2013 Aue fold Vehicles with a V6 petrol engine and automatic gearbox are equipped
43. ase with assembly paste 88 Rep gr 47 Brakes hydraulics Audi A8 2003 gt GANN Brake system Edition 03 2013 Aue 3 2 Removing and installing pistons for front brake caliper Special tools and workshop equipment required Removal wedge VAS 3409 00 0016 Assembly paste gt Parts catalogue Assembly tool for protective caps T10146 5 FT 0 4 6 Piston resetting appliance T10145 Removing Force piston out of brake caliper housing using compressed air Item 1 Piston resetting appliance T10145 a Note Place a piece of wood in the recess to prevent damaging the pis ton A47 0190 3 Brake calipers 2FNR 42 AL 89 WOO Audi A8 2003 gt Au Brake system Edition 03 2013 Lever off protective cap from brake caliper e g with removal wedge 3409 Take out seal Todo this use wedge 3409 2 Item 1 Piston resetting appliance T10145 Note When removing ensure that the surface of the cylinder is not damaged Installing The surface of the piston and seal should be cleaned using only methylated spirits and then dried Apply a small amount of assembly paste to piston and seal before inserting Insert inner seal in groove in brake caliper housing with re moval wedge 3409 Press in protective cap with special tool 1 and 2 Item 1 Assembly tool for protective caps 1 10146 5 Item 2 Piston resetting app
44. c Renew brake disc cording to wear indicators 4 J 2 Wear assessment according to wear indicators gt page 11 None of the six wear indicators fully worn out gt brake disc OK One of the six wear indicators fully worn out Ooo e S e SO Renew brake disc 3 Assessing degree of wear on ceramic brake discs 9 vuy Audi A8 2003 gt Au Brake system Edition 03 2013 Note Depending on the version the minimum permissible weight for a used brake disc is stamped on the brake disc hub The disc must be renewed when the weight of the disc is less than or equal to the indicated minimum weight Always renew brake discs on both Sides of the axle AN Caution If the minimum permissible weight of the disc is indicated on the hub of the disc min weight the disc must be additionally weighed to assess the amount of wear The disc must be re newed when the weight of the disc is less than or equal to the indicated minimum weight Brake disc with minimum weight stamped on hub 1 Wear assessment by checking thickness of brake disc if minimum weight is stamped on hub gt page 11 Thickness of brake discs in permissible range gt brake disc OK Brake disc thickness in critical Value at or below limit range min Th 0 05 mm ir Further wear assessment ac Renew brake disc cording to wear indicators 4 4 2 Wear assessment according to wear indicators gt page 11 None of the six wear indicato
45. cking bolt Q Tightening torque 35 Nm Q Always renew Q Counter hold guide pin when loosening and tightening 4 Brake caliper OY Do not disconnect brake hose when changing brake pads Q Servicing brake caliper gt page 101 5 Brake pads Q Always renew onyboth sides of axle Q Removing and installing gt page 67 Q Checking pad thickness gt Maintenance Book A46 0323 66 Rep gr 46 Brakes mechanism meee Audi A8 2003 gt C 0 Brake system Edition 03 2013 Aue let 8E 6 Pad retainer Q Always renew when changing pads 7 Brake disc Q Always renew on both sides of axle Q Detach brake caliper prior to removing Q Only dress evenly on both sides starting from thickness when new page 1 Q Allocation of brake discs gt page 1 Ribbed bolt Tightening torque 140 Nm M12x1 5 x 75 Always renew Set torque wrench V A G 1332 to 125 Nm to tighten the bottom bolt This tightening torque only applies when using insert tool T40036 00 1 OOOO 9 Brake carrier with guide pins and protective caps Q Replacement carriers are supplied assembled and with sufficient grease on guide pins Q If protective caps or guide pins are damaged renew using repair kit Use grease sachet supplied to lubricate guide pins 10 Brake line Q Tightening torque 14 Nm Q Do not disconnect brake line when changing brake pads 11 Retaining spring Q Make sure that the loc
46. cking pad thickness gt Maintenance Book let 4E a Note Clean the brake calipers thoroughly grease tree before ingerting new brake pads When doin this make sure that all adhesive foi i the contact surfaces fof the outer brake pad is removed A46 0251 46 Rep gr 46 Brakes mechanism meee Audi A8 2003 gt 44y Brake system Edition 03 2013 Aue 2 Brake carrier Q Bolt to wheel bearing housing 3 Ribbed bolt m 190 Nm Q Clean ribs if using again O M14 x 1 5 x 38 4 Bearing bush Q Insert into brake caliper housing 5 Guide pin m Tightening torque 30 Nm 6 Protective cap m Q Take off Insert wear indicator wire in protective cap 7 Brake disc O O OG Wear limit gt page 1 Always renew on both sides of axle Detach brake caliper prior to removing Lightly grease contact surfaces between brake disc and wheel hub with polycarbamide grease G 052 142 A2 8 Wheel bolts m Fitting wheels gt Wheel Tyre Guide 9 Brake line connection at brake pipe m Tightening torque 12 Nm a Note Brake line connection at brake pipe 12 Nm Brake pipe in brake caliper 19 Nm 10 Brake line m m m m Screw into brake caliper housing Screw into brake hose counter hold on brake hose hexagon Do not twist hose when fitting Ensure that lugs are properly seated in grooves in bracket 11 Brake pipe in brake caliper
47. d impair brake operation The consequences of a contaminated brake system only become ap parent months later and then give rise to greater expenses particularly in vehicles equipped with ABS A Sleeve original size B Sleeve swollen due to contact with mineral oil Summary of the above mentioned points Always keep brake fluid containers properly sealed This is the only way of preventing contamination by oil dirt cleaning agents or moisture Brake fluid containers should be kept completely separate from oils including hydraulic fluid and cleaning agents to prevent any mixture of fluids or even filling of the brake system with an incor rect fluid Audi A8 2003 gt COG Brake system Edition 03 2013 Auer c 300 250 200 150 1005 4 3 4 5 Gew Wasser N47 0016 B 5 Brake fluid 1 T COLD Audi A8 2003 gt Au Brake system Edition 03 2013 45 Anti lock brake system 1 General information on the anti lock brake system 1 1 Notes for repair work on the ABS The anti lock brake system is basically maintenance free Testing removing installing and repair work may only be per formed by qualified personnel Failure to observe the information described in this Workshop Manual may result in damage to the system and could make the vehicle unsafe Before carrying out repair work on the anti lock brake system determine the cause of the problem using self diagnosis
48. d on brake hose hexagon Q Do not twist hose when fitting Q Ensure that lugs are properly seated in grooves in bracket 11 Brake pipe in brake caliper Q Tightening torque 19 Nm Note Brake line at brake hose 12 Nm Brake pipe in brake caliper 19 Nm 40 Rep gr 46 Brakes mechanism meee Audi A8 2003 gt 44y Brake system Edition 03 2013 Aue 12 Bracket Q Bolt to brake caliper housing Q Attach brake line 13 Bolt for bracket QO 25Nm 14 Brake caliper Q If assembly work is required do not leave caliper hanging from brake hose but secure it to body with wire Q With the exception of Removing and installing brake pads gt page 41 and Servicing front brake caliper gt page 84 no repairs may be performed on the brake caliper Q Do not twist hose when fitting Q Allocation gt page 1 Brakes 15 Q 1 3 Renewing brake caliper page 45 Retaining spring Q Note correct installation position Q Engage onto both brake caliper housing studs and onto outer pad retaining spring a Note The retaining spring must be push ed under the brake carrier after en gaging onto both studs If incorrectly installed the wear of the outer pad cannot be adjusted and the pedal travel will be increased as a result 1 2 Removing and installing brake pads Check the thickness of the brake disc when renewing the brake pads Refer to wear limit for brake disc Wear limit gt
49. di A8 2003 gt Au Brake system Edition 03 2013 AN Caution On vehicles with ceramic brakes the wheel must not be allowed to drop onto the brake disc This would cause irreparable dam age to the disc Screw two assembly pins from vehicle tool kit into the wheel bolt holes when removing and fitting a wheel Insert the long assembly pin into the top hole Remove brake pads gt page 57 Detach brake caliper gt page 60 Do not leave brake caliper hanging from brake hose but secure it to bodywork using a suitable cable tie or wire Take care that brake hose is not damaged by weight of brake components Remove locating bolt 6 from brake disc holding brake disc in position Take brake disc off wheel hub Note Take care to keep the brake disc straight when taking it off the wheel hub Installing Clean contact surfaces of wheel hub and remove corrosion Fit brake disc onto wheel hub Note Take care to keep the brake disc straight when fitting it onto the wheel hub Screw in locating bolt 6 and tighten to 5 Nm Attach brake caliper gt page 60 Install brake pads gt page 57 Fit wheels AN Caution On vehicles with ceramic brakes the wheel must not be allowed to drop onto the brake disc This would cause irreparable dam age to the disc Screw two assembly pins from vehicle tool kit into the wheel bolt holes when removing and fitting a whe
50. draulics V A G 1331 V A G 1331 meee Audi A8 2003 gt C 0 Brake system Edition 03 2013 Auer 11 7 Removing and installing vacuum pump 2 8 Itr and 3 2 Itr petrol engine Removing Pull off front engine cover panel arrows AN Caution Take care not to damage the vacuum hose The vacuum hose must be renewed if it is damaged Unclip vacuum line leading to air cleaner at vacuum pump housing Disconnect vacuum hose 1 from vacuum pump Remove bolts arrows and take off vacuum pump Installing Installation is performed in reverse sequence note the following a Note Renew O rings Secure all hose connections with the correct type of hose clips SN gee same as original equipment gt Electronic parts catalogue QOS Set drive lug of vacuum pump 1 so it engages in symmetrical slot in camshaft when vacuum pump is installed arrows A15 10075 11 Vacuum pumps for brake servo 1 31 vuy Audi A8 2003 gt Au Brake system Edition 03 2013 Attach vacuum pump to flange arrows and tighten bolts to 9 Nm Slide new hose clip onto vacuum hose Push vacuum hose 1 onto connection on vacuum pump AN Caution Take care not to damage the vacuum hose The vacuum hose must be renewed if it is damaged lt S A15 10066 Use suitable pliers to fasten clip on vacuum hose
51. e When minimum weight is stamped on hub of brake disc f the thickness is x min Th 0 05 mm additionally check the wear of the brake disc by inspecting the wear indicators page 11 All types of ceramic brake discs continued If the thickness of the brake disc is less than or equal to the min imum permissible thickness min Th do NOT continue using the brake disc The brake disc must be renewed In this case always renew the brake discs on both sides of the axle When doing so always renew the brake pads on both sides of the axle 3 2 Wear assessment according to wear in dicators Wear indicators are positioned at intervals of 120 degrees on the friction surface of the brake disc 3 Assessing degree of wear on ceramic brake discs 1 1 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 The wear indicators arrow appear in a different colour There are three indicators on each side of the brake disc front and reverse side The wear of the indicators is visible as a dark burnt out recess Do NOT continue using the brake disc if one of the six indicators is completely burnt out The brake disc must be renewed In this case always renew the brake discs on both sides of the axle When doing so always renew the brake pads on both sides of the axle Checking area of bolted connection on friction ring and brake disc hub AN WARNING The brak
52. e brake pedal Installing Installation is carried out in the reverse sequence when doing this note the following Attaching brake pedal to brake servo Hold ball head of push rod in front of mounting and push brake pedal towards brake servo so that ball head audibly locks into place Adjust brake light switch brake pedal switch gt page 34 AN Caution Before driving vehicle for the first time make sure function of brakes is OK 76 Rep gr 46 Brakes mechanism meee Audi A8 2003 gt C 0 Brake system Edition 03 2013 Aue 6 Removing and installing mounting bracket 6 1 Removing and installing mounting bracket Removing gt Rep gr 92 Servicing windscreen wiper system Removing and installing wiper system Remove driver s storage compartment gt Body Repairs Rep gr 68 Removing and installing brake servo gt page 117 Remove brake light switch gt page 34 Separate brake pedal from brake servo page 74 Remove bolt connections 1 Item 2 Mounting bracket Item 3 Bulkhead Remove accelerator pedal Unscrew hexagon socket head bolts gt Item 7 page 74 Removing brake pedal mounting bracket Remove Torx socket head bolt T45 gt Item 5 page 74 item 4 Installing Installation is carried out in the reverse sequence when doing this note the following Attaching brake pedal to brake servo Hold ball head of
53. e disc ring and the brake disc hub are bolted together and must NOT be separated Do NOT slacken the bolted con nection on the brake disc hub 3 3 Wear assessment by weighing brake disc Special tools and workshop equipment required Commercially available scales with a tolerance of 1 g Procedure Remove front brake disc for weighing Remove rear brake disc for weighing e The brake disc must be cleaned and dry before itis weighed AN Caution Do NOT clean the brake disc with water or other fluids as this will falsify the results Note The brake disc ventilation drillings must be completely free of dirt Clear out carefully with a suitable tool if necessary Thoroughly blow out the brake discs with compressed air in cluding the area between the cooling channels and ventilation arillings Carefully place the clean brake disc on the scales The initial weight of the brake disc with disc brake hub is engraved on the disc brake hub For this model the following maximum values are specified for brake disc weight loss Front brake disc Up to 120 g weight loss from initial weight of new brake disc 1 2 Rep gr 00 Technical data eee Audi A8 2003 gt 44 Brake system Edition 03 2013 Auer Rear brake disc Up to 120 g weight loss from initial weight of new brake disc a Note If the weight loss is only 20 g within these limits additionally check the wear of the b
54. e sure not to damage the compressor nut Piston resetting appliance T10145 can also be used to press in the brake piston Make sure that the protective cap is located in the groove of the brake piston when the piston is pressed in all the way Insert pad retaining springs Measure the pad thicknesses of both brake pads without back plates and make a note of the lower value a Note Round off the measured value to a whole number The value should be between 3 and 14 Use new brake pads if the measured value is less than 3 Fit brake pads 6 Rear brake calipers for electronic parking brake and handbrake EPB 1 05 WOO Audi A8 2003 gt Au Brake system Edition 03 2013 Ensure that the brake pads are located correctly in the pad retainers arrows Secure brake caliper housing with new self locking bolts Note The repair kit includes four self locking hexagon boltswhichimust always be installed Fit electronic parking brake connector into bracket Switch on ignition Apply and release electronic parking brake three times Wait in each case until the actuator motors of the electronic parking brake have reached their end position Switch ignition off and on again after 10 seconds gt Self di agnosis Address word 53 Parking brake Display on VAS 505x Select function 04 Basic setting 1 06 Rep gr 47 Brakes hydraulic
55. e vehicle and select the parking brake via self diagnosis with Address word 53 When doing this the ignition must be off Note gt gt Ignition on Release parking brake Coding checked and rectified if necessary Event memory interrogated indicated faults eliminated and memory erased Display on VAS 505x Select function 04 Basic setting Display on VAS 505x The prompt to enter a display group appears in display zone Display zone 2 shows a keypad Enter 7 to select Display group 007 via the keypad in dis play zone 2 and confirm entry with 9 key brake opens all the way 1 02 Rep gr 47 Brakes hydraulics Audi A8 2003 gt GANN Brake system Edition 03 2013 Auer Remove securing bolts from brake caliper housing when do ing this counter hold on guide pins a Note Do not unplug connection of actuator motor or brake system Push connector out of retainer Move brake caliper clear to one side Remove brake pads Remove guide clips gt Self diagnosis Address word 53 Park ing brake Display on VAS 505x Select function 04 Basic setting Display on VAS 505x The prompt to enter a display group appears in display zone Display zone 2 shows a keypad Enter 6 to select Display group006 via the keypacbin dis play zone 2 and confirm entry with o key
56. eave brake caliper and brake carrier hanging from brake hose but secure them to bodywork using a suitable cable tie or wire Take care that brake hose is not damaged by weight of brake components Note Do NOT loosen bolts 1 62 Rep gr 46 Brakes mechanism Audi A8 2003 gt C 0 Brake system Edition 03 2013 Auer Remove locating bolt 6 from brake disc holding brake disc in position Take brake disc off wheel hub mee Take care to keep the brake disc straight when taking it off the wheel hub Installing Clean contact surfaces of wheel hub and brake disc and re move corrosion Fit brake disc onto wheel hub a Note Take care to keep the brake disc straight when fitting it onto the wheel hub Screw in locating bolt 6 and tighten to 5 Nm 16 17 18 Attach brake caliper gt page 60 ASS Fit wheels Tightening torque for wheel bolts gt Rep gr 44 AN Caution Before driving vehicle for the first time make sure function of brakes is OK 3 6 Renewing front brake disc ceramic brakes AN WARNING The brake disc ring and the brake disc hub are bolted together and must NOT be separated Do NOT slacken the bolted con nection on the brake disc hub a Note Always renew on both sides of axle Removing Raise vehicle Remove wheels 3 Ceramic front brakes PR 1LW 63 wuy Au
57. ec tion from vacuum pump A Caution Take care not to damage the vacuum hose The vacuum hose must be renewed if it is damaged Remove bolts arrows and take off vacuum pump Installing Installation is performed in reverse sequence note the following Note Renew O rings Set drive lugs of vacuum pump so they engage in slots in camshaft when vacuum pump is installed arrows Attach vacuum pump to flange arrows and tighten bolts to 9Nm A15 10036 1 22 Rep gr 47 Brakes hydraulics pee Audi A8 2003 gt 444 Brake system Edition 03 2013 Auer Secure vacuum hose to vacuum pump with bolt 1 5 Nm AN Caution Take care not to damage the vacuum hose The vacuum hose must be renewed if it is damaged Tightening torques Component M Vacuum pump to timing chain cover 9 Hose connection for vacuum hose to vacuum 5 pump 11 3 Vacuum pump exploded view 4 0 Itr TDI 1 10 Nm 2 Vacuum pump Removing and installing gt page 124 3 Vacuum hose Q Secure with hose clips same as original equip ment gt Electronic parts catalogue 4 Hose clip a Note On some models the v has to be secured at th pump with a bolt 5 O ring Q Renew 6 O ring Q Renew 7 Inlet camshaft A15 0980 11 Vacuum pumps for brake servo 1 23 COLD Audi A8 2003 gt Auo _Brake system Edition 03 2013 11 4 Removing and i
58. ece at windscreen cross mem ber Unplug connector from sender for float warning indicator vt Pull off vacuum hose 2 1 1 8 Rep gr 47 Brakes hydraulics meee Audi A8 2003 gt C 0 Brake system Edition 03 2013 Auer Unscrew securing bolt 1 for brake fluid reservoir a Note Protect the plenum chamber against any brake fluid which es capes The underside of the brake fluid reservoir clips into the brake master cylinder Foremoverreservoir press down locking lug and atthe same time pull brake fluid reservoir out of Sealing plugs Pull off brake fluid reservoir and lay it to one side Disconnect brake lines 2 and seal with sealing plugs from repair kit Part No 1HO 698 311A Removing and installing brake light switch gt page 34 Separate brake pedal from brake servo page 74 Unscrew securing bolts for brake servo 1 Remove brake servo with brake master cylinder 10 Removing and installing brake servo 1 1 9 wuy Audi A8 2003 gt Au Brake system Edition 03 2013 Unscrew securing nuts for brake master cylinder 1 Carefully remove brake master cylinder from brake servo Installing When installing note the following points in particular Before installing brake master cylinder clean any residual brake fluid off plenum chamber When assembling brake master cylinder with brake servo unit make sure push rod
59. een cross member ltem 4 Support connection piece at windscreen cross mem ber 9 Removing and installing brake master cylinder 1 1 5 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 Unscrew securing bolt 1 for brake fluid reservoir Pull off brake fluid reservoir and lay it to one side Note Protect the plenum chamber against any brake fluid which es capes The underside of the brake fluid reservoir clips into the brake master cylinder To remove reservoir press down locking lug and atthe same time pull brake fluid reservoir out of sealing plugs Disconnect brake lines 2 and seal with sealing plugs from repair kit Part No 1HO 698 311 A Unscrew securing bolts for brake master cylinder 3 Carefully remove brake master cylinder from brake servo Installing When installing note the following points in particular Before installing brake master cylinder clean any residual brake fluid off plenum chamber When assembling brake master cylinder with brake servo unit make sure push rod is properly positioned in brake master cylinder Adjust brake light switch gt page 34 Bleed brake system gt page 110 AN Caution Before driving vehicle for the first time make sure function of brakes is OK 1 1 6 Rep gr 47 Brakes hydraulics Audi A8 2003 gt GNNN Brake system Edition 03 2013 Aue 10 Removing and installing bra
60. el Insert the long assembly pin into the top hole Tightening torque for wheel bolts gt Rep gr 44 AN Caution Before driving vehicle for the first time make sure function of brakes is OK 64 Rep gr 46 Brakes mechanism Audi A8 2003 gt GAN Brake system Edition 03 2013 Aue 4 Rear brakes electronic parking brake and handbrake EPB gt 4 1 Servicing rear brakes all models including ceramic brakes Page 65 4 1 Servicing rear brakes all models in cluding ceramic brakes Steel version brakes Check the thickness of the brake disc when renewing the brake pads Refer to wear limit for brake disc gt 1 Brakes wear limits page 1 Ceramic brakes The ceramic brake discs must always be checked for damage and wear when renewing the brake pads 2 Assessment of ceramic brake discs page 4 gt 3 Assessing degree of wear on ceramic brake discs page 7 a Note Install all parts supplied in repair kit 4 Rear brakes electronic parking brake and handbrake EPB 65 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 1 Self locking bolt QO Tightening torque 12 Nm 2 Actuator motor for electron ic parking brake and hand brake Removing and installing control unit for electro mechanical parking brake gt page 79 Removing and installing actuator motor gt page 79 3 Self lo
61. ep gr 46 Brakes mechanism Audi A8 2003 gt GNNN Brake system Edition 03 2013 Aue 47 Brakes hydraulics 1 Pressurised leak test 1 1 Pressurised leak test Special tools and workshop equipment required Tester for brake pressure regulator V A G 1310 A V A G 1310 A W00 0562 V A G 1310 1 2 High pressure and low pressure tests Before starting Make sure that the brake system master cylinder brake hoses brake lines and brake calipers works properly and is free of leaks High pressure test Remove bleeder screw at one of the front brake calipers Con nect pressure gauge V A G 1310 or tester for brake pres sure regulator V A G 1310 A and bleed Insert brake pedal depressor between brake pedal and driver s seat Apply pressure to brake pedal until the gauge indicates a pressure of 50 bar The pressure must not drop by more than 4 bar during the test period of 45 seconds Renew hydraulic unit if drop in pressure exceeds the above figure V A G 1310 Low pressure test Move the brake pedal depressor back until the pressure gauge indicates a pressure of 6 bar The pressure should not drop by more than 1 bar within the test period of 3 minutes Renew hydraulic unit if drop in pressure exceeds the above figure 1 Pressurised leak test 83 CAVV Audi A8 2003 gt Au Brake system Edition 03 2013 2 Brake calipers FNR G60 2 1 Servicing brake calipers
62. etters Confirm the entered information Wait until the tester has interrogated all the control units in the vehicle Press the button and select the option Function com ponent selection Select Running gear on the display Select Brake system on the display Select 01 Self diagnosis compatible systems on the dis play Select Anti lock brake system on the display Select Function on the display You will now see displayed all possible functions for the anti lock brake system installed in the vehicle Select the function you require on the display 2 Connecting VAS 505x and selecting functions 2 1 COLD Audi A8 2003 gt Auo _Brake system Edition 03 2013 3 Electronic stabilisation program Bosch 5 7 3 1 Overview of components ESP Bosch 5 7 1 ABS hydraulic unit N55 with ABS control unit with EDL J104 Q The hydraulic unit and the control unit together form the hydraulic con trol unit Q Do notdisconnectcon nector 42 pin before successfully completing self diagnosis Switch off ignition before de taching connector Q Located on the hydraul ic unit on left of engine compartment Q Removing and installing gt page 24 2 Brake pressure sender 01435 1 G201 Q Screws onto hydraulic unit Q Removing and installing gt page 36 3 TCS ASR ESP button E256 Q Fitting location in centre console 4 Latera
63. extending piston The piston extends for 20 seconds and drops out of the brake caliper Note If the brake piston has not dropped out after 20 seconds switch ignition off and on again after 10 seconds Then operate the switch for the electronic parking brake The brake piston will ex tend for another 20 seconds Switch off ignition Take brake piston and compressor nut out of brake caliper Detach the old protective cap from the brake piston 6 Rear brake calipers for electronic parking brake and handbrake EPB 1 03 CAVV Audi A8 2003 gt Au Brake system Edition 03 2013 Remove the old seal from the brake caliper using removal wedge 3409 Installing Fit the new seal in the brake caliper Fit the new protective cap onto the brake piston as shown in the illustration Screw compressor nut 1 into brake caliper onto stop then turn nut a quarter turn in the opposite direction Insert protective cap into groove in brake caliper To do this use removal wedge 3409 Carefully slide brake piston into brake caliper Turn brake pis ton as required The brake piston must be guided over the compressor nut which is only possible in four positions 1 04 Rep gr 47 Brakes hydraulics Audi A8 2003 gt GNNN Brake system Edition 03 2013 Auer Press brake piston onto stop in brake caliper after passing the compressor nut a Note Mak
64. f it is damaged Release clip in direction of arrow and remove Pull vacuum pump for brakes V192 upwards out of bracket Installing Installation is carried out in the reverse sequence J MTT 12 3 Checking vacuum pump for brakes V192 Special tools and workshop equipment required Vehicle diagnosis and service information system VAS 505x VAS 5051 Hpk WiOO O7 06 Procedure With ignition switched off connect vehicle diagnosis service and information system VAS 505x to diagnostic connection 1 34 Rep gr 47 Brakes hydraulics ee ee Audi A8 2003 gt COG Brake system Edition 03 2013 Auer Switch on tester arrow The tester may need up to 3 minutes before it is ready for oper ation Switch on ignition Select mode Press the button on the display for Vehicle self diagnosis Select vehicle system Press the button for Engine electron ics The control unit identification and coding will appear at the top right of the display Select diagnosis function all diagnosis functions are available at this stage Select 006 Basic setting on the display Press buttons 0 7 and 1 for Measured value block Confirm entry with o key The following information will appear at the bottom of the display Basic setting Not operated Firmly depress the brake pedal several times in succession u
65. fluid level and top up if necessary AN Caution Before driving vehicle for the first time make sure function of brakes is OK 2 Front brakes PR 1LJ 1LL 1LM 1LK 53 ANP Audi A8 2003 gt Auer Brake system Edition 03 2013 3 Ceramic front brakes PR 1LW gt 3 1 Servicing ceramic brakes page 54 3 1 Servicing ceramic brakes The ceramic brake discs must always be checked for damage and wear when renewing the brake pads 2 Assessment of ceramic brake discs page 4 gt 3 Assessing degree of wear on ceramic brake discs page 7 Note Always install all parts supplied in repair kit After renewing brake pads depress brake pedal firmly several times with vehicle stationary so that the pads are properly seated in their normal operating position To draw off brake fluid from brake fluid reservoir use a bleeder bottle which is used only for brake fluid Brake fluid is poison ous and must NOT be drawn off by sucking through a hose 1 Bolts Caution Do NOT loosen these bolts Note the brake caliper 2 Retaining spring for brake pads 3 Guide pin 4 Brake caliper QO If assembly work is re quired do not leave cal iper hanging from brake hose but secure it to body with wire Q With the exception of Renewing brake pads gt page 48 and Servic ing front brake caliper gt page 88 no repairs may be performed on
66. fore driving vehicle for the first time make sure function of brakes is OK 4 Rear brakes electronic parking brake and handbrake EPB 73 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 5 Brake pedal LHD exploded view AN WARNING The brake pedal travel must not be restricted by additional floor coverings Lubricate all bearings and contact surfaces with grease Part No G 000 450 02 1 Hexagon bolt 2 Brake pedal mounting bracket 3 Hexagon nut Q Tightening torque 25 Nm 4 Torx socket head bolt T45 Q Tightening torque 25 Nm 5 Tube 6 Brake pedal Q Insert tube gt Item 5 page 74 Q Removing and installing gt page 76 7 Hexagon socket head bolt Q Tightening torque 9 Nm Q The 3 hexagon head bolts locate the acceler ator pedal module from the other side 8 Accelerator pedal 9 Torx socket head bolt T45 Q Tightening torque 40 Nm 10 Spacer sleeve Q With bonded gasket 11 Mounting bracket for pedal cluster Q Illustration for automatic gearbox 12 Mounting Q For ball head of brake servo push rod 13 Bearing shell 14 Insulation cover 5 1 Separating brake pedal from brake ser vo Special tools and workshop equipment required 74 Rep gr 46 Brakes mechanism Brake system Edition 03 2013 Auer T10159 Release tool Remove driver s footwell cover gt Rep gr 68 General body repairs
67. fy cloths Only remove replacement parts from packaging immediately prior to installation Only use genuine spare parts from original packaging When the system is open do not work with compressed air and do not move the vehicle 1 8 Rep gr 45 Anti lock brake system eee Audi A8 2003 gt 44 Brake system Edition 03 2013 Aue Ensure that no brake fluid enters electrical connectors 1 General information on the anti lock brake system 1 9 COLD Audi A8 2003 gt Auo _Brake system Edition 03 2013 2 Connecting VAS 505x and select ing functions Special tools and workshop equipment required Vehicle diagnostic testing and information system VAS 505x Diagnosis lead 3m with power supply VAS 5051 1 AN WARNING Test equipment must always be secured to the rear seat when road testing the vehicle While the vehicle is moving this equipment must be oper ated by a second person NOT by the driver Attach the diagnosis cable connector VAS 5051 5a to the di agnosis connection 20 Rep gr 45 Anti lock brake system ee ee Audi A8 2003 gt COG Brake system Edition 03 2013 Auer The tester is ready as soon as a picture of a car appears in the display gt Oe O Switch on the tester arrow Switch on ignition Press the Guided Fault Finding button on the display screen Select the following Make Model Model year Version Engine code l
68. g brake 7 Piston Removing and installing gt page 101 8 Guide pin Q Lubricate before instal 1 00 Rep gr 47 Brakes hydraulics Pou Audi A8 2003 gt 44y Brake system Edition 03 2013 Aue ling protective cap 9 Protective cap Q Insert onto brake carrier and guide pin 10 Brake carrier with guide pins and protective caps Q Replacement carriers are supplied assembled and with sufficient grease on guide pins Q If protective caps or guide pins are damaged renew using repair kit Use grease sachet supplied to lubricate the guide pins 11 Protective cap Q Removing and installing gt page 101 Q Push outer sealing lip onto piston 6 2 Removing and installing piston for rear brake caliper Applies to steel and ceramic brakes V A G 1331 V A G 1332 el V A G 1551 VAS 5051 Special tools and workshop equipment required 6 Rear brake calipers for electronic parking brake and handbrake EPB 1 0 1 YY Audi A8 2003 gt Auer Brake system Edition 03 2013 gt gt Oo V A G 1331 Torque wrench V A G 1332 Torque wrench T10145 Piston resetting appliance VAS 505x Vehicle diagnosis testing and information system 3409 Removal wedge Removing Raise the vehicle Remove wheels Connect vehicle diagnostic testing and information system VAS 505x with diagnosis lead VAS 5051 1 to the 16 pin diagnosis connector of th
69. g sequence for vehicles with Electronic Stabilisation Program ESP Changingpbrake dluidyright Copying for private or commercial purposes in part or in whale is Mot a a a ee ee ee Brake servo brake master cylinder exploded VIEW copyrigetoy AUDI AG eee eee ee eee Removing and installing brake master cylinder 000 c eee eee Removing and installing brake master cylinder 0 0 02 ee Removing and installing brake servo 0 0 cette eens Removing and installing brake servo 1 eee Vacuum pumps for brake servo 1 eee eens Vacuum pump exploded view 3 0 Itr TDI 000202 eee Removing and installing vacuum pump 3 0 Itr TDI 2 ee Vacuum pump exploded view 4 0 Itr TDI 0 00022 eee Removing and installing vacuum pump 4 0 Itr TDI 2 ee Vacuum pump exploded view 4 2 Itr TDI 00000 eee eee Removing and installing vacuum pump 4 2 Itr TDI ee Removing and installing vacuum pump 2 8 Itr and 3 2 Itr petrol engine Audi A8 2003 gt GNNM Brake system Edition 03 2013 Aue 12 12 1 12 2 12 3 12 4 12 5 13 13 1 13 2 14 14 1 14 2 Electric vacuum pump for brakes V192 6 eee eens 133 Vacuum pump for brakes V192 exploded view 0 cc ees 133 Removing and installing vacuum pump for brakes V192 1 2 ee 133 Checking vacuum pump for brakes V192 ee 134 Removing and installing brake servo pressure
70. he straight end of the jaws must face the spindle otherwise the flanged connection on the brake line will not be formed correctly C o lt VAS 6056 7 N47 10069 14 2 Instructions for use Applies to steel and ceramic brakes Unscrew defective brake line at brake caliper or wheel brake cylinder Catch escaping brake fluid and dispose of fluid in the correct manner 1 40 Rep gr 47 Brakes hydraulics ee ee Audi A8 2003 gt 444 Brake system Edition 03 2013 Auer Cut through brake line at a suitable point straight easily ac cessible section of pipe using pipe cutter 2 Remove section of pipe to be replaced De grease outside surface of brake lines Clamp brake line in mole grips 4 so that approx 50 mm of pipe protrudes from plastic jaws Clamp brake line scraper tool 3 in electric drill and apply tool to brake_line With electric drill running at slow speed exert light pressure and strip off coating from brake line The length of the coating that is stripped off is determined by the limit stop incorporated in the brake line scraper tool Pull scraper tool off brake line and clean off residue of coating Remove mole grips and slide union screw D onto brake line Push brake line B against limit stop A in flanging tool cane The brake line must be in contact with the limit stop when the
71. iers a Note On some models the vacuum hose has to be secured at the vac uum pump with a bolt AN Caution Take care not to damage the vacuum hose The vacuum hose must be renewed if it is damaged Tightening torque Component Nm Vacuum pump to timing chain cover 11 Vacuum pumps for brake servo 1 25 COLD Audi A8 2003 gt Auo _Brake system Edition 03 2013 11 5 Vacuum pump exploded view 4 2 Itr TDI 1 10Nm 2 Vacuum pump Removing and installing gt page 127 3 Vacuum hose Q Secure with hose clips same as original equip ment gt Electronic parts catalogue 4 Hose clip Note On some models the v has to be secured at th pump with a bolt 5 O ring Q Renew 6 O ring Q Renew 7 Inlet camshaft A15 0980 1 26 Rep gr 47 Brakes hydraulics Audi A8 2003 gt GANN Brake system Edition 03 2013 Aue 11 6 Removing and installing vacuum pump 4 2 Itr TDI Special tools and workshop equipment required V A G 1331 V A G 1331 1 Torque wrench V A G 1331 Ratchet V A G 1331 1 i Tool insert 19 mm V A G EES 1331 5 Tool insert 17 mm V A G 1331 6 V A G 1331 5 V A G 1331 6 3615 10024 Removing Drain off coolant Carefully pull engine cover panel off four mounting studs one at a time arrows AN Caution Observe rules for cleanliness when working
72. ifferent versions avail able gt Parts catalogue Q Always renew on both sides of axle Q gt 1 2 Removing and in stalling brake pads page 41 Q Checking pad thickness gt Maintenance Book let 4E Note Clean the brake calipers thoroughly grease free before ingerting new brake pads When doing this make sure that all adhesive fall residue on the contact surfaces fon the outer brake pad is removed A46 0218 1 Front brakes PR 1LG 39 COLD Audi A8 2003 gt Auo _Brake system Edition 03 2013 2 Brake carrier Q Bolt to wheel bearing housing 3 Ribbed bolt Q Tightening torque 190 Nm Q Clean ribs if using again Q M14 x1 5 x 38 4 Bearing bush Q Insert into brake caliper housing 5 Guide pin Q Tightening torque 30 Nm 6 Protective cap Q Take off Q Insert wear indicator wire in protective cap 7 Brake disc Q Wear limit gt page 1 Q Always renew on both sides of axle Q Detach brake caliper prior to removing Q Lightly lubricate contact surfaces between brake disc and wheel hub with polycarbamide grease gt Parts catalogue Q Allocation of brake discs gt page 1 8 Wheel bolts Q Fitting wheels gt ELSA Wheel Tyre Guide 9 Brake line connection at brake pipe Q Tightening torque 12 Nm Note Brake line at brake pipe 12 Nm Brake pipe in brake caliper 19 Nm 10 Brake line Q Screw into brake caliper housing Q Screw into brake hose counter hol
73. ight is stamped on hub of brake disc gt 3 4 Wear assessment by weighing brake disc page 13 AN WARNING The brake disc ring and the brake disc hub are bolted together and must NOT be separated Do NOT slacken the bolted con nection on the brake disc hub Checking area of bolted connection on friction ring and brake disc hub Designation of ceramic brake disc on brake disc hub 3 Assessing degree of wear on ceramic brake discs T Y Audi A8 2003 gt Au Brake system Edition 03 2013 1 Direction of rotation 2 Supplier 3 Serial production number of brake disc 4 Audi part number Note pending on the vehicle model 5 Production date of brake disc 6 Permissible minimum thick ness of brake disc Note on the type of vehicle 7 Weight of new brake disc with brake disc hub Checking area of bolted con nection on friction ring and brake disc hub AN WARNING The brake disc ring and the brake disc hub are bolted together and must NOT be separated Do NOT slacken the bolted connection on the brake disc hub Note Depending on the version the min imum permissible weight for a used brake disc is stamped on the brake disc hub The disc must be renewed when the weight of the disc is less than or equal to the indicated mini mum weight Always renew brake discs on both sides of the axle AN Caution If the minimum permissi ble weight of the di
74. is properly positioned in brake master cylinder Adjust brake light switch gt page 34 Bleed brake system gt page 110 AN Caution Before driving vehicle for the first time make sure function of brakes is OK 1 20 Rep gr 47 Brakes hydraulics meee Audi A8 2003 gt C 0 Brake system Edition 03 2013 Aue 11 Vacuum pumps for brake servo Removing and installing vacuum pump 3 0 Itr diesel engine gt page 122 Removing and installing vacuum pump 4 0 Itr diesel engine gt page 124 Removing and installing vacuum pump 4 2 Itr diesel engine gt page 127 Removing and installing vacuum pump 2 8 Itr and 3 2 Itr petrol engine gt page 131 Electric vacuum pump for brake servo V192 petrol engines gt page 133 11 1 Vacuum pump exploded view 3 0 Itr TDI 1 9 Nm 2 Vacuum pump Q Removing and installing gt page 122 3 Vacuum hose Q Secure with hose clips same as original equip ment gt Electronic parts catalogue 4 5 Nm 5 O ring Renew 6 Inlet camshaft 7 O ring Q Renew 8 O ring Q Renew A151078 11 Vacuum pumps for brake servo 1 2 1 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 11 2 Removing and installing vacuum pump 3 0 Itr TDI Removing Carefully pull engine cover panel off 4 mounting studs one at a time arrows l 4 A10 10093 Remove bolt 1 and detach vacuum hose with hose conn
75. ke pads C Then engage damper springs A left and right in guide pin B using commercially available pliers AN Caution Make sure that the damper springs are fitted correctly at the guide pin and brake pads Installation position of damper springs at guide pin and brake pads arrows Connect wear indicator connector and insert wire in dust cap and protective cap Note Itis important to ensure that thejpad wearinaicator wire Is inserted in the retaining spring 2 Insert pad wear indicator wire in retaining spring 2 Fit wheels gt ELSA Wheel Tyre Guide gt Rep gr 44 Check brake fluid level and top up if necessary AN Caution After installing the brake pads and before driving the vehicle depress brake pedal firmly several times with the vehicle sta tionary so that the brake pads are properly seated in their normal operating position AN Caution Before driving vehicle for the first time make sure function of brakes is OK 3 4 Removing and installing brake caliper ceramic brakes AN Caution Do NOT loosen bolts 1 60 Rep gr 46 Brakes mechanism Audi A8 2003 gt Yi Brake system Edition 03 2013 Auer 4 Brake caliper QO If assembly work is re quired do not suspend caliper from brake hose but tie it to body with a piece of wire 10 Bolts a Note Always renew if removen Oh 190 Nm
76. ke servo 10 1 Removing and installing brake servo Special tools and workshop equipment required Brake filling and bleeding equipment VAS 5234 VAS 5234 woo 1104 or Brake filling and bleeding equipment V A G 1869 A Sealing plugs repair kit part No 1HO 698 311A Removing Remove storage compartment on driver s side gt Body Re pairs Rep gr 68 Detach plenum chamber cover Drawing off brake fluid with brake filling and bleeding equipment V A G 1869 or VAS 5234 Open brake fluid reservoir As protection against escaping brake fluid place a sufficient number of lint free cloths in area beneath brake master cylin der 10 Removing and installing brake servo 1 1 T ee CO Audi A8 2003 gt Au Brake system Edition 03 2013 Draw off as much brake fluid as possible from brake fluid res ervoir using brake filling and bleeding equipment VAS 5234 or extraction unit V A G 1869 4 SS VAS 5234 Removing body brace Remove bolts with washers 1 tightening torque 45 Nm Remove bolts with washers 2 tightening torque 3 Nm ltem 3 Front section of plenum chamber ltem 4 Suspension turret Arrow in illustration points in direction of travel iy Z JZ A47 0180 Remove bolts with washers 1 tightening torque 9 Nm ltem 2 Cross piece for suspension turret ltem 3 Windscreen cross member ltem 4 Support connection pi
77. king lug is fitted properly in the bracket 4 2 Removing and installing brake pads rear brakes Steel version brakes Check the thickness of the brake disc when renewing the brake pads Refer to wear limit for brake disc gt 1 Brakes wear limits page 1 Ceramic brakes The ceramic brake discs must always be checked for damage and wear when renewing the brake pads 2 Assessment of ceramic brake discs page 4 gt 3 Assessing degree of wear on ceramic brake discs page i 4 Rear brakes electronic parking brake and handbrake EPB 67 Audi A8 2003 gt Auo _ Brake system Edition 03 2013 V A G 1331 V A G 1332 at We iak e T10145 A oN VAS 5051 _ G46 0004 Special tools and workshop equipment required Torque wrench V A G 1331 Torque wrench V A G 1332 Piston resetting appliance T10145 Vehicle diagnostic testing and information system VAS 505x Insert tool T40036 Removing Note Mark brake pads when removing them if they are to be rein stalled Fit in same position when installing otherwise uneven braking will be caused It is recommended to apply the electronic parking brake after driving long distances Pad wear is automatically adjusted approx every 1 000 km 68 Rep gr 46 Brakes mechanism Audi A8 2003 gt Ye Brake system Edition 03 2013 Auer Select jacking mode g
78. l acceleration sender 01423 G200 and yaw rate sender 01542 G202 Q Combined in one hous ing Q Fitting location under 13 12 11 g extension of centre con A450165 sole Q Can be checked in Guided Fault Finding with vehicle diagnostic testing and information system VAS 505x Q Observe installation instructions gt page 35 22 Rep gr 45 Anti lock brake system meee Audi A8 2003 gt C 0 Brake system Edition 03 2013 Aue 5 Traction control system warning lamp 00824 3424 K86 Q Location In the dash panel insert Q See Owner s Manual for further information 6 ABS warning lamp K47 Q Location In the dash panel insert Q See Owner s Manual for further information 7 Brake system warning lamp K118 Q Fitting location in driver information system dash panel insert Q See Owner s Manual for further information 8 Parking brake switch F234 Q Fitting location in centre console Q Removing and installing gt page 36 9 Steering angle sender 00778 3132 G85 vehicles with ESP Q Fitting location incorporated in return ring with slip ring on steering column gt Body Repairs Rep gr 69 Q Performing zero compensation Vehicle diagnostic testing and information system VAS 505x 10 Wheel bearing hub unit Q The ABS sensor ring is installed in the wheel bearing 11 Rear right left speed sensor G44 G46 Q Can be checked in Guided Fault Finding with vehic
79. le diagnostic testing and information system VAS 505x Q Renewing page 32 12 Diagnostic socket Q Fitting location cover in driver s footwell 13 Brake light switch F and cruise control system brake pedal switch diesel direct injection system 00629 Q Removing and installing gt page 34 Q Can be checked in Guided Fault Finding with vehicle diagnostic testing and information system VAS 505x 14 Wheel bearing hub unit Q The ABS sensor ring is installed in the wheel bearing 15 Front right left speed sensor G45 G47 Q Can be checked in Guided Fault Finding with vehicle diagnostic testing and information system VAS 505x Q Renewing page 31 16 Brake fluid level warning contact F34 17 Tandem brake servo 3 Electronic stabilisation program Bosch 5 7 23 COLD Audi A8 2003 gt Auo _Brake system Edition 03 2013 3 2 Hydraulic unit and brake lines 1 Brake master cylinder and brake servo 2 Brake line Q Brake master cylinder primary piston circuit to hydraulic unit 3 Brake line Q Brake master cylinder secondary piston circuit to hydraulic unit 4 Brake line Q Hydraulic unit to front right brake caliper 5 Brake line Q Hydraulic unit to front left brake caliper 6 Brake line Q Hydraulic unit to rear left brake caliper 7 Brake line Q Hydraulic unit to rear right brake caliper 8 Brake pressure sender 01435 1 G201 Q Screws
80. led with brake fluid and are pre bled Apply a thin coat of lithium grease G 052 150 AZ to brake cylinder piston and seal 1 Dust cap Q Fit onto bleeder valve 2 Bleeder valve 12 Nm Q Before screwing in grease thread with thin coat of lithium grease G 052 150 A2 3 Brake caliper 4 Seal for 32 mm piston Removing and installing gt page 93 5 Seal for 28 mm piston Removing and installing gt page 93 6 Piston 32 mm Q Removing and installing gt page 93 Q Apply a thin coat of lithi um grease G 052 150 A2 to piston 7 Piston 28 mm Q Removing and installing gt page 93 Q Apply a thin coat of lithi um grease G 052 150 A2 to piston 8 Protective cap for 32 mm piston Do not damage when in serting piston 9 Protective cap for 28 mm A47 0182 piston Q Do not damage when inserting piston 92 Rep gr 47 Brakes hydraulics Audi A8 2003 gt Ye Brake system Edition 03 2013 Aue 10 Support plate 11 Hexagon socket head bolt 6 Nm 12 Connecting pipe 17 Nm 4 2 Removing and installing pistons for front brake caliper Special tools and workshop equipment required Removal wedge 3409 00 0016 Piston resetting appliance T10145 Lithium grease G 052 150 A2 Removing Force pistons out of brake caliper housing one at a time using compressed air The pistons can only be removed one at a time Hold the opposite pi
81. liance T10145 Use jaw protectors Push protective cap onto brake caliper housing and press it in so that it is seated flush arrow Use jaw protectors A47 0192 90 Rep gr 47 Brakes hydraulics eee Audi A8 2003 gt 444 Brake system Edition 03 2013 Auer Atthis stage it should not be possible to remove the protective cap from the brake caliper housing by hand Apply a small amount of assembly paste to piston and seal before inserting Lift up piston with standard extension and ratchet attachment as shown in illustration and press lightly onto protective cap Keep the piston straight to avoid damaging the seal Inflate protective cap with compressed air maximum 3 bar The protective cap will then locate around the brake piston Use jaw protectors Press piston into brake caliper housing by hand Note The inner sealing lip on the protective cap will then locate in the piston groove AN Caution Before driving vehicle for the first time make sure function of brakes is OK 3 Brake calipers 2FNR 42 AL 9 1 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 4 Brembo brake calipers 18 4 1 Servicing brake calipers Brake line connection at brake pipe 12 Nm Brake pipe in brake caliper 19 Nm Note Use only methylated spirits to clean the brake caliper nstall complete repair kit when servicing New brake calipers are fil
82. lling brake discs note direction of travel indicated by arrow on brake disc and fitting location left or right Raise the vehicle Remove wheels 48 Rep gr 46 Brakes mechanism Audi A8 2003 gt GNNN Brake system Edition 03 2013 Auer Secure brake disc with one wheel bolt see arrow Lever brake pad retaining spring out of brake caliper housing with a screwdriver and remove a Note Spring is under tension so protect yourself by holding a glove or cloth in front of spring Unplug connector for brake pad wear indicator as shown in illustration Turn connector 90 while using a screwdriver to release con nector from bracket Pull connector upwards out of bracket and detach wire 2 Front brakes PR 1LJ 1LL 1LM 1LK 49 CAVV Audi A8 2003 gt Au Brake system Edition 03 2013 Detach brake line from bracket Remove caps 1 nT Ue Unscrew and remove both guide pins from brake caliper Take off brake caliper housing and lay to one side so that the weight of the brake caliper does not stress or damage the brake hose Take brake pads out of brake caliper housing or from brake carrier Note The brake pad with wear indicator is located on the inside Remove brake carrier when renewing brake discs Use only methylated spirits to clean the brake caliper housing Installing Check the thickness of the brake di
83. luid from the reservoir with a bleeder bottle Otherwise fluid can overflow and cause damage particularly if the reservoir has been topped up AN WARNING Brake fluid is poisonous and must NOT be drawn off by sucking through a hose Remove retaining spring 2 Remove brake pads from brake caliper housing Use only methylated spirits to clean the brake caliper housing Installing The ceramic brake discs must always be checked for damage and wear when renewing the brake pads 2 Assessment of ceramic brake discs page 4 gt 3 Assessing degree of wear on ceramic brake discs page T Insert brake pads into brake caliper a Note The brake pad with the wear indicator wire is located on the inside Insert retaining spring in brake caliper housing 2 Press guide pin 3 through brake caliper and brake pads AN WARNING After introducing the guide pin the retaining spring must be pressed underneath th guide pin so that itis under tension If the retaining spring is fitted incorrectly the brake pads will be out of position and the function of the brakes will be impaired Tighten bolt of guide pin 18 to specified torque gt Item 18 page 56 3 Ceramic front brakes PR 1LW 59 vuy Audi A8 2003 gt Au Brake system Edition 03 2013 First engage damper springs A left and right in bottom hole in corresponding bra
84. motor Q Removing and installing gt page 101 8 Acoustic signal Q Warning signal if parking brake is operated while vehicle is in motion Q Warning signal if a fault is detected in the system 78 Rep gr 46 Brakes mechanism 7 Audi A8 2003 gt GNNN Brake system Edition 03 2013 Auer 7 1 Removing and installing control unit for electronic parking brake and handbrake Removing Remove battery Pull locking slide in direction of arrow and unplug connector Item 2 EPB control unit Remove nuts 1 Remove item 2 EPB control unit Installing Installation is carried out in the reverse sequence when doing this note the following Screw on nuts 1 tightening torque 10 Nm When renewing the control unit select the function Replace for the relevant control unit in the Guided Fault Finding Vehicle diagnostic testing and information system VAS 505x AN Caution Before driving vehicle for the first time make sure function of brakes is OK 7 2 Removing and installing actuator motor for electronic parking brake and hand brake Special tools and workshop equipment required Torque wrench V A G 1331 V A G 1331 7 Overview of components electronic parking brake and handbrake EPB 79 C amp G Audi A8 2003 gt u _Brake system Edition 03 2013 Vehicle diagnostic testing and information system VAS 505x Remo
85. n in operation while the vehicle is being driven must not be fitted a second time Push control unit onto ABS hydraulic unit N55 and screw in new bolts 1 and 2 evenly without tightening until control unit makes even contact with hydraulic unit Screw in bolts 1 to 6 all the way but do not tighten Tighten bolts 1 to 6 in the sequence shown Tightening torque 2 9 Nm After tightening check that all bolt heads are seated flush Install assembled unit gt page 27 30 Rep gr 45 Anti lock brake system A4S 10047 A46 10048 A46 10048 pe Audi A8 2003 gt 44 Brake system Edition 03 2013 Aue 4 Removing and installing parts of ABS system on front and rear axles 4 1 Removing and installing parts of ABS system on front axle 1 ABS speed sensor QO Before inserting sensor clean inner surface of fit ting hole and coat with grease G 000 650 Q Renewing page 31 2 Hexagon socket head bolt Q Tightening torque 18 Nm 3 Drive shaft 4 Wheel hub with wheel bear ing 5 Hexagon socket head bolt Q Always renew if re moved Rep gr 40 Servicing drive shaft A45 0173 4 1 1 Removing and installing front wheel speed sensor Removing Raise the vehicle 4 Removing and installing parts of ABS system on front and rear axles 3 1 C amp D Audi A8 2003 gt Au Brake system Edition 03 2013 Unplug connecto
86. newing ABS control unit J104 2 tee 28 4 Removing and installing parts of ABS system on front and rear axles 205 31 4 1 Removing and installing parts of ABS system on front axle 000 31 4 2 Removing and installing parts of ABS system on rear axle 002000005 32 5 Removing and installing parts of ESP system 0 ccc ees 34 5 1 Removing and installing brake light switch 0 0 0 0 eee 34 5 2 Removing and installing lateral acceleration sender G200 and yaw rate sender G202 35 5 3 Removing and installing steering angle sender G85 ww ee 35 5 4 Removing and installing parking brake switch 0 ee 36 5 5 Removing and installing brake pressure sender G201 200000 0c eee 36 46 gt Brakes MGcnanism esse ddaiar h raea meiaes Veeck dae eeeeuia deb E EAE 38 1 Front brakes PRALG cies negu ele Oe bean bee Pd a dee es Dae ead eee 38 1 1 Servicing front brakes ceca aiost Shad aaa Lae ee das whee ea PR eee AN 38 1 2 Removing and installing brake pads 6 eee 41 1 3 Renewing brake caliper 0 ec eee eee 45 2 Front brakes PR 1LJ 1LL 1LM 1LK 0 0 ees 46 2 1 Servicing front brakes 2 eee 46 2 2 Removing and installing brake pads 6 eee 48 2 3 Renewing brake caliper sesir isos iodide ee eee ke ee Pe dhe ee 52 3 Ceramic front brakes PR 1LW 0 cece eee eee eee 54 Contents i COLD Audi A8 2003 gt Auo _ Brake system Edition 03 2013
87. nstalling vacuum pump 4 0 Itr TDI Removing Carefully pull engine cover panel off four mounting studs one at a time arrows er ee OOH Remove cover for suspension turret right side to do so de tach fasteners 1 and unscrew retainer 2 Pull cover out of retainer clamps arrows AN Caution Observe rules for cleanliness when working on the injection system Disconnect fuel return line 1 and fuel supply line 2 at fuel filter Unplug electrical connector arrow at fuel temperature sender G81 and move fuel lines to one side 1 24 Rep gr 47 Brakes hydraulics Audi A8 2003 gt GNNN Brake system Edition 03 2013 Auer Disconnect vacuum hose 1 from vacuum pump AN Caution Take care not to damage the vacuum hose The vacuum hose must be renewed if it is damaged Remove bolts 2 and 3 Take off vacuum pump Installing Installation is performed in reverse sequence note the following Note Renew O rings Secure all hose connections with the correct type of hose clips same as original equipment gt Electronic parts catalogue Set drive lugs of vacuum pump so they engage in slots in camshaft when vacuum pump is installed Attach vacuum pump to flange and tighten bolts to 9 Nm Fit new hose clip onto vacuum hose Push vacuum hose 1 onto connection on vacuum pump Fasten hose clip using suitable pl
88. ntil the test is activated The following information will appear at the bottom of the display Basic setting Not operated Pump on Xxx mbar Test on Do not press the brake pedal again once the test has been acti vated The vacuum pump for brakes V192 supplies vacuum to the brake servo The diagnosis of the brake servo system runs in the control unit at the same time The system passes the test if the pressure in the brake servo reaches the shut off threshold within the time limit set by the di agnostic function The following information will appear at the bottom of the display Basic setting Not operated You can cancel or exit from this mode by pressing the Go to button 12 Electric vacuum pump for brakes V192 1 35 Y Audi A8 2003 gt Auer Brake system Edition 03 2013 The system fails the test if the pressure in the brake servo does not reach the shut off threshold within the time limit set by the diagnostic function The following information will appear at the bottom of the display Basic setting Not operated Pump off xxx mbar Syst n OK Perform Guided Fault Finding using vehicle diagnosis and service information system VAS 505x 12 4 Removing and installing brake servo pressure sensor G294 Removing Unplug connector 1 aoa pry out and remove brake servo pressure sensor Installing Installation is carried out in the reverse sequence 12
89. ompressed air maximum 3 bar The protective cap will then locate around the brake piston Use jaw protectors Press piston into brake caliper housing by hand Note i a lt LA The inner sealing lip on the protective cap will then locate in the piston groove AN Caution Before driving vehicle for the first time make sure function of brakes is OK 2 Brake calipers FNR G60 87 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 3 Brake calipers 2FNR 42 AL 3 1 Servicing brake calipers nstall complete repair kit when servicing Apply a thin coat ofassembly paste to brake cylinders pistons and seals gt Parts catalogue 1 Brake carrier Q Bolt to brake caliper housing 2 Guide pin Q Tightening torque 30 Nm 3 Caps Q Insert into bearing bush 4 Protective cap Q Push onto bleeder valve 5 Bleeder valve Q Tightening torque 10 Nm Q Before screwing in grease thread lightly with lithium grease gt Parts catalogue 6 Bearing bush Q Insert into brake caliper housing 7 Brake caliper 8 Retaining spring Q Note correct installation position Q Engage onto both brake caliper housing studs and onto outer pad re taining spring 9 Protective cap Q Do not damage when in A47 0200 serting piston Q Apply a thin coat of lithium grease 10 Piston Q Apply a thin coat of lithium grease to piston Q Allocation gt page 1 11 Seal Q Gre
90. on the injection system 11 Vacuum pumps for brake servo 1 27 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 Disconnect fuel return line 1 and fuel supply line 2 at fuel filter Unplug electrical connector arrow at fuel temperature sender G81 and move fuel lines to one side Slacken off union nuts 1 and 3 Remove bolt 2 and take off high pressure pipe Detach electrical connector 1 ba Remove bolts arrows and detach exhaust gas recirculation EN aN amp ae EA control motor V339 left side ot 1 28 Rep gr 47 Brakes hydraulics Audi A8 2003 gt GNNN Brake system Edition 03 2013 Auer Remove bolt 4 and detach coolant connection Detach hoses 2 and 6 Remove bolts 1 3 and 5 and detach connection for ex haust gas recirculation Detach coolant hose arrow in front of bulkhead Disconnect vacuum hose 1 from vacuum pump AN Caution Take care not to damage the vacuum hose The vacuum hose must be renewed if it is damaged Remove bolts 2 and 3 and take off vacuum pump Installing Installation is performed in reverse sequence note the following a Note Renew seals and O rings Secure all hose connections with the correct type of hose clips same as original equipment gt Electronic pa
91. or electronic parking brake and handbrake EPB 1 09 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 7 Bleeding brake system A WARNING Do not under any circumstances allow brake fluid to come oe contact with fluids that contain mineral oils e g oil petrol cleaning agents Mineral oils damage the plugs and seals in the brake system Brake fluid is poisonous and must NOT be drawn off by sucking through a hose Because of its caustic properties it must also not come into contact with paintwork Brake fluid is hygroscopic i e itabsorbs moisture from the surrounding air and should therefore always be stored in airtight containers Brake fluid flushed out during the bleeding process must not be re used and must be disposed of in the proper manner Always observe the relevant environmental regulations for disposal gt page 17 Note Only use new brake fluid conforming to US standard FMVSS 116 DOT 4 Genuine VW Audi brake fluid conforms to this specification Do not use liquids containing silicone Avoid contamination of brake fluid with any dirt particles or bits of fluff e g from cleaning cloths etc Rinse off spillages using plenty of water When the system is open do not work with compressed air and do not move the vehicle During the final road test ensure that at least one ABS con trolled braking operation is performed pulsations must be felt at the brake pedal 7
92. r 1 Remove bolt 2 from wheel bearing housing Pull ABS speed sensor out of wheel bearing housing Installing Before inserting speed sensor clean inner surface of hole and coat speed sensor thoroughly with lubricating paste G 000 650 Insert speed sensor into drilling in wheel bearing housing and tighten bolt Connect speed sensor to speed sensor wiring 4 2 Removing and installing parts of ABS system on rear axle 1 Drive shaft 2 Bracket For speed sensor wire 3 Hexagon socket head bolt 18 Nm Q Tightening torque 18 Nm 4 ABS speed sensor QO Before inserting sensor clean inner surface of fit ting hole and coat with grease G 000 650 Q Renewing page 32 5 Wheel bearing hub unit Q The ABS sensor ring is installed in the wheel bearing 6 Hexagon socket head bolt Q Always renew if re moved gt Rep gr 42 Servicing rear drive shaft A45 0174 4 2 1 Removing and installing rear wheel speed sensor Removing Raise the vehicle 32 Rep gr 45 Anti lock brake system ee ee Audi A8 2003 gt 444 Brake system Edition 03 2013 Aue Detach speed sensor wiring connector 1 from speed sensor Remove bolt 2 from wheel bearing housing Pull ABS speed sensor out of wheel bearing housing Installing Before inserting speed sensor clean inner surface of fitting hole and coat speed sensor thoroughly with grease G 000 650
93. r brake disc Check brake disc for wear gt 1 Brakes wear limits page 1 Press piston back a Note Before inserting new brake pads press piston back into cylinder with resetting appliance Before pressing the piston back draw off brake fluid from the reservoir with a bleeder bottle Otherwise fluid can overflow and cause damage particularly if the reservoir has been subsequently topped up AN WARNING Brake fluid is poisonous and must NOT be drawn off by sucking through a hose Insert brake pad with retaining spring and wear indicator into brake caliper housing piston 1 Front brakes PR 1LG 43 Y Audi A8 2003 gt Au Brake system Edition 03 2013 Fit outer brake pad 2 in brake caliper Note Fit brake pads into brake caliper and install assembly on brake carrier brake disc Secure brake caliper housing to brake carrier with both guide pins tighten to 30 Nm Make sure not to twist the brake hose when installing Fit both caps Insert retaining spring into brake caliper housing Attach brake line Connect wear indicator connector and insert wire in dust cap and protective cap Fit wheels gt ELSA Wheel Tyre Guide gt Rep gr 44 Note The retaining spring must be pushed under the brake carrier after engaging onto both studs If incorrectly installed the wear of the outer pad cannot be adjusted and
94. rake disc according to the wear indicators If the weight loss has reached or exceeded these limits the brake discs must be renewed It is no longer permissible to use these brake discs The brake disc must be renewed Always renew brake discs on both sides of axle if the brake discs have to be renewed because of wear there has been a technical modification to the replacement brake disc indicated by changed part number In this case always renew the brake discs on both sides of the axle When doing so always renew the brake pads on both sides of the axle 3 4 Wear assessment by weighing brake disc Brake disc with minimum weight stamped on hub Special tools and workshop equipment required Commercially available scales with a tolerance of 1 g Procedure Remove front brake disc for weighing Remove rear brake disc for weighing ae Depending on the version the minimum permissibleweight fora used brake disc is stamped on the brake dise hubi The adiscmust be renewed when the weight of the disc is less than or equal to the indicated minimum weight Always renew brake discs on both sides of the axle e The brake disc must be cleaned and dry before it is weighed AN Caution Do NOT clean the brake disc with water or other fluids as this will falsify the results a Note The brake disc ventilation drillings must be completely free of dirt Clear out carefully with a suitable tool if necessary
95. rake disc wear there has been a technical modification to the replacement brake disc indicated by changed part number Always renew brake discs on both sides of axle gt page 63 When doing so always renew the brake pads on both sides of the axle gt page 57 2 5 Chipping on ceramic brake discs Always renew ceramic brake discs if there is chipping larger than 1 cm arrow on the friction surface Always renew brake discs on both sides of axle gt page 54 if renewal is necessary because of brake disc wear there has been a technical modification to the replacement brake disc indicated by changed part number Always renew brake discs on both sides of axle gt page 63 When doing so always renew the brake pads on both sides of the vehicle gt page 57 2 6 Cracks extending into cooling channels Always renew ceramic brake discs if there is a crack extending from the friction surface of the brake disc to the cooling channel or through the cooling channel arrow gt page 54 A0O 10367 6 Rep gr 00 Technical data meee Audi A8 2003 gt C 0 Brake system Edition 03 2013 Aue 3 Assessing degree of wear on ceramic brake discs gt 3 1 Wear assessment by checking thickness of brake disc page 11 gt 3 2 Wear assessment according to wear indicators page 11 gt 3 3 Wear assessment by weighing brake disc page 12 When minimum we
96. rake system Brake system Edition 03 2013 Auer 5 2 Removing and installing lateral acceler ation sender G200 and yaw rate send er G202 The lateral acceleration sender G200 and the yaw rate sender G202 are integrated in one housing The housing is located on the front tunnel below the air conditioner Removing Remove extension of centre console gt Rep gr 68 General body repairs interior Pull connector off lateral acceleration yaw rate sender Remove the two securing bolts arrows Take out lateral acceleration yaw rate sender Installing AN WARNING Severe shocks or jolts can damage the lateral acceleration yaw rate sender Installation is carried out in the reverse sequence When installing ensure lateral acceleration yaw rate sender is correctly seated in its bracket and is free of stress Do not use the securing bolts to forcibly position the lateral ac celeration yaw rate sender Tighten securing bolts to 10 Nm When renewing the control unit select the function Replace for the relevant control unit in the Guided Fault Finding To do so use the testing and information system 5 3 Removing and installing steering angle sender G85 The steering angle sender is located between the steering wheel and steering column switch 5 3 1 Removing and installing gt Rep gr 48 gt Vehicle diagnostic testing and information sy
97. rier Q Bolt to wheel bearing housing 12 Brake pistons WARNING The brake pistons have different diameters When re installing please make sure that each of the brake pistons is inserted in the correct aperture in the brake cal iper The ceramic inserts on the brake piston act as heat insulators and must not be separated from the brake piston If the ceramic insert is damaged the brake pis tons must be renewed for safety reasons 13 Bolt for bracket O Tightening torque 25 Nm 14 Brake iline connection at brake pipe Q Tightening torque 12 Nm Q Brake hose must not be twisted Note Brake line connection at brake pipe 12 Nm Brake pipe in brake caliper 19 Nm 96 Rep gr 47 Brakes hydraulics meee Audi A8 2003 gt C 0 Brake system Edition 03 2013 Aue 15 Brake line Q Screw into brake caliper housing Q Screw into brake hose counter hold on brake hose hexagon Q Do not twist hose when fitting Q Ensure that lugs are properly seated in grooves in bracket 16 Bracket for brake line Q Bolt to brake caliper housing Q Attach brake line 17 Brake pipe in brake caliper Q Tightening torque 19 Nm a Note Brake pipe in brake caliper 19 Nm Brakedineyconnectioniat brake pipe 12Nm 18 Bolt for guide pin Q Tightening torque 30 Nm 19 Damper spring Q 2 fitted on each brake caliper Q Detaching and attaching gt page 57 5 2 Removing and
98. rque Item 2 Brake hose Item 3 Retaining spring Item 4 Brake hose bracket A47 0178 13 2 Tightening torques Splash plates to wheel bearing housing 10 Nm Hydraulic unit with bracket to longitudinal mem 10 Nm ber Bosch 5 7 Bleed valve to brake caliper 10 Nm Brake pipe to brake hoses 15 Nm Rear brake caliper EPB brake hose to brake 38 Nm caliper banjo union with banjo bolt Brake caliper to brake carrier 35 Nm Brake carrier to wheel bearing housing always 140 Nm renew bolts See note gt Item 8 page 67 1 38 Rep gr 47 Brakes hydraulics meee Audi A8 2003 gt C 0 Brake system Edition 03 2013 Auer 14 Repairing brake lines With the aid of the flanging tool for brake lines VAS 6056 it is possible to make connections on the ends of the brake lines with out damaging the coating In certain cases this makes it possible to replace sections of brake lines and thus save repair costs The flanging tool set V A G 1356 must not be used for the black brake lines because of the coating and the diameter of these brake lines a Note Donot bend brake lines more than 90 this would cause kinks or other deformations which would excessively restrict the brake lines Brake lines should preferably be cut at some point on the un derside of the vehicle Select the position of the connecting pieces so that they can not chafe against any moving parts Do not grea
99. rs fully worn out gt brake disc OK Eo fully worn out Se eS Weigh brake disc page 13 Minimum weight not reached Pee NNO Po BrakediscOK Po Minimum weight reached _ O o e l ee ee L o a Renew brake disc Always renew brake discs on both sides of axle if the brake discs have to be renewed because of wear there has been a technical modification torthereplacement brake disc indicated by changed parttnumber 1 0 Rep gr 00 Technical data meee Audi A8 2003 gt C 0 Brake system Edition 03 2013 Aue If one of the three wear limits defined below has been reached do NOT continue using the brake disc The brake disc must be renewed In this case always renew the brake discs on both sides of the axle When doing so always renew the brake pads on both sides of the axle 3 1 Wear assessment by checking thick ness of brake disc Special tools and workshop equipment required Use a commercially available caliper gauge or micrometer gauge The minimum permissible thickness of the brake disc is engraved as min Th on the brake disc hub Measure the brake disc thickness at three points round the outside of the disc next to the individual wear indicators x a Note If the thickness is x min Th 0 2 mm additionally check the wear of the brake disc by inspecting the wear indicators gt page 11 When minimum weight is stamped on hub of brake disc Ge
100. rts catalogue Set drive lugs of vacuum pump so they engage in slots in camshaft when vacuum pump is installed arrows 11 Vacuum pumps for brake servo 1 29 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 Attach vacuum pump to flange and tighten bolts to 9 Nm Fit new hose clip onto vacuum hose Push vacuum hose 1 onto connection on vacuum pump Close hose clip using suitable pliers Note On some models the vacuum hose has to be secured at the vac uum pump with abolt AN Caution Take care not to damage the vacuum hose The vacuum hose must be renewed if it is damaged Tighten union nuts on high pressure pipes hand tight initially Make sure high pressure pipes are seated without strain Use torque wrench V A G 1331 with ratchet V A G 1331 1 and tool insert 17 mm V A G 1331 6 to tighten high pres sure pipe connection at high pressure pump Use torque wrench V A G 1331 with ratchet V A G 1331 1 and tool insert 19 mm V A G 1331 5 to tighten high pres sure pipe connections at rail elements Install exhaust gas recirculation control motor V339 left side Fill cooling system Tightening torque Vacuum pump to timing chain cover EGR connection to Cylinder head Connecting pipe 9 Coolant connection to EGR connection High pressure pipe to High pressure pump Rail element 1 30 Rep gr 47 Brakes hy
101. s 0000 cece eee 6 2 6 Cracks extending into cooling channels 200 00 cece eee tee 6 3 Assessing degree of wear on ceramic brake discs 0 000 e eee ees 7 3 1 Wear assessment by checking thickness of brake disc 0000 ce eee eee 11 3 2 Wear assessment according to wear indicators 0 0 eee 11 3 3 Wear assessment by weighing brake disc 00 000 cee eee eee eens 12 3 4 Wear assessment by weighing brake disc 000 000s 13 4 Braktea sO eee eee e eben ben eeeeenens 15 4 1 Geieral nofesk PAR QAR ee eee eee 15 4 2 Vehicles with front wheel drive 2 0000 cece eee 15 4 3 Vehicles with four wheel drive 0 002 eee 15 4 4 EPB Electronic Parking Brake on brake dynamometer 02 05 15 5 Brakeatluide Rian E ete 17 5 1 General Notes 24 beta 64dee baa geet ade ee be belies Miedo be ee kee dees 17 45 Anti lock brake system 0000 eens 18 1 General information on the anti lock brake system 0000 0 cece eee 18 1 1 Notes for repair work onthe ABS 0000 eee eee 18 2 Connecting VAS 505x and selecting functions 0 0 0 eee eee 20 3 Electronic stabilisation program Bosch 6 700 ee 22 3 1 Overview of components ESP Bosch 5 7 200 0c cece eee 22 3 2 Hydraulic unit and brake lines 0 eee 24 3 3 Removing and installing hydraulic control unit 0 0 0 0 eee 24 3 4 Re
102. s Audi A8 2003 gt GNNN Brake system Edition 03 2013 Auer Display on VAS 505x The prompt to enter a display group appears in display zone Display zone 2 shows a keypad Enter 10 to select Display group 10 via the keypad in dis play zone 2 and confirm entry with o key system test The operation of the brake is tested The electronic parking brake opens all the way and closes three times gt Self diagnosis Address word 53 Parking brake Display on VAS 505x Select function 10 Adaption Display on VAS 505x Prompt for entering channel number appears in display zone Display zone 2 shows a keypad Enter 6 to select Channel number 06 via the keypad in dis play zone 2 and confirm entry with 9 key entering brake pad thickness Display on VAS 505x Read and test channel 6 appears in display zone 1 Zone 2 displays the specified limits for brake pad thickness Zone 3 displays a sliding bar diagram with a number repre senting the currently stored pad thickness The pad thickness can be changed within the specified limits 3 14 via the sliding bar Note fyou enter a pad thickness that is outside the specified limits via the sliding bar the valuewill be indicated but not accepted The display resets automatically if th pad thickness entered via the sliding bar
103. s tem VAS 505x Guided Fault Finding function Zero position compensation of steering angle sender must then be performed Connect vehicle diagnostic testing and information system VAS 505x and select Function component selection with the Go to key Then under Function select Replace steering angle sender 00778 3132 G85 gt page 20 meee Audi A8 2003 gt 44y a Ww N45 0302 5 Removing and installing parts of ESP system 35 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 5 4 Removing and installing parking brake switch Removing Remove extension of centre console gt Rep gr 68 General body repairs interior Remove switch item 2 from navigation unit ltem 1 bolt 2x tightening torque 8 Nm Unplug connector item 3 Installing Installation is carried out in the reverse sequence 5 5 Removing and installing brake pressure sender G201 Removing Note Cover the engine compartment to ensure that no brake fluid flows into it Remove hexagon bolt 1 securing fluid reservoir and pull fluid reservoir to the side and out of buffer Tightening torque 6 Nm Unplug connector 1 36 Rep gr 45 Anti lock brake system meee Audi A8 2003 gt C G Brake system Edition 03 2013 Auer Unscrew brake pressure sender 4 Installing Remaining installation steps are
104. sc is indicated on the hub of the disc min weight the disc must be addi tionally weighed to as sess the amount of wear 8 Rep gr 00 Technical data gt 075095 A xs A 00 1042226 See eae Audi A8 2003 gt C 0 Brake system Edition 03 2013 Auer Caution Always install brake discs of the same type on both sides of one axle The brake disc must first be cleaned before assessing the degree of wear as described below AN WARNING Do NOT clean the brake disc with water or other fluids as this will falsify the results a Note The brake disc ventilation drillings must be completely free of brake dust and dirt Clear out carefully with a suitable tool if necessary Do not use force Thoroughly blow out the brake discs with compressed air in cluding the area between the cooling channels and ventilation arillings AN Caution Always observe respiratory protection requirements when cleaning brake discs orother parts of thebrakesystemusing compressed air To assess the brake disc wear proceed as follows 1 Wear assessment by checking thickness of brake disc 2 Wear assessment according to wear indicators 1 Wear assessment by checking thickness of brake disc gt page 11 Thickness of brake discs in permissible range gt brake disc OK Brake disc thickness in critical Value at or below limit range min Th 0 2 mm E Further wear assessment a
105. sc when renewing the brake pads Refer to wear limit for brake disc Check brake disc for wear gt 1 Brakes wear limits page 1 50 Rep gr 46 Brakes mechanism Audi A8 2003 gt GNNN Brake system Edition 03 2013 Auer Press back both pistons a Note Before inserting new brake pads press pistons back into cylin ders with resetting appliance Before pressing the pistons back draw off brake fluid from the reservoir with a bleeder bottle Oth erwise fluid can overflow and cause damage particularly if the reservoir has been topped up AN WARNING Brake fluid is poisonous and must NOT be drawn off by sucking through a hose Insert brake pad with retaining spring and wear indicator into brake caliper housing piston Fit outer brake pad 2 in brake caliper a Note Fit brake pads into brake caliper and install assembly on brake carrier brake disc 2 Front brakes PR 1LJ 1LL 1LM 1LK 51 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 Secure brake caliper housing to brake carrier with both guide pins tighten to 30 Nm Fit both caps Make sure not to twist the brake hose when installing Insert retaining spring into brake caliper housing Attach brake line Connect wear indicator connector and insert wire in dust cap and protective cap Fit wheels gt ELSA Wheel Tyre Guide gt Rep gr 44 Note
106. se the spindle clean with methylated spirits only Special tools and workshop equipment required Flanging tool for brake lines VAS 6056 List of tools in set Item Tool T00L number 1 Flanging tool including jaws VAS 6056 1 VAS 6056 6 Pipe cutter VAS 6056 2 3 Brake line scraper tool VAS 6056 3 Mole grips with plastic jaws VAS 6056 4 Pipe bending tool VAS 6056 5 6 Allen key 6 mm Co s Jaws for flanging tool VAS 6056 7 3 The grub screws in the stem and on the sides of the tool are pre set and must not be turned 14 Repairing brake lines 1 39 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 14 1 Flanging tool exploded view 1 Top section of flanging tool Q Unscrew this part to change jaws of flanging tool 2 Mounting for handle Q Must be removed for ac cess to retaining screw for top section of tool 3 Retaining screw For top section of flang ing tool 4 Grub screws for jaws Q These screws centralise and secure jaws of flanging tool Q 2mm socket head 5 Jaws for flanging tool Q Different versions avail able Q Assembly instructions gt page 140 N4 10068 Assembly instructions for jaws of flanging tool VAS 6056 6 dark for black brake lines VAS 6056 7 light for green brake lines lt a VAS 6056 6 Note The arrow on the rounded end of the jaws must face the end of the housing and t
107. sensor G294 2 2 4 136 Checking non return valve 61 teens 136 Brake hoses and brake lines 1 0 0 0 0 0c eens 137 Routing oftbrake hosesilines AN AR eens 137 Tightemigg tarques 9 NG VB ce eee 138 Repairing brake lings J A8 J J eee eee eee eee eens 139 Flanging tool exploded view WIL A c eee eee eae 140 INSTUCHONSUOL LUSCH N MgO eee 140 Contents III COLD Audi A8 2003 gt Auo _ Brake system Edition 03 2013 IV Contents Audi A8 2003 gt Coe Brake system Edition 03 2013 Aue 00 Technical data 1 Brakes wear limits ARL003290 Edition 03 2013 Brake system Diagonally split dual circuit braking system with ABS EBPD EDL ASR ESP ECD and EPB Front brakes Brake caliper FNR FNRG60 FNR42AL FNR42AL FNR42AL G60 16 17 18 18 16 Factory code PR No 1LL 1LM 1LJ 1LK Ventilated brake disc Brake caliper piston mm 60 6o 2x42 2x42 2x42 Brake pad wear limit in mm cluding backplate and damper plate 1 Special security vehicle gt 1 Front brakes PR 1LG page 38 gt 2 Front brakes PR 1LJ 1LL 1LM 1LK page 46 a Note When performing repair work on brakes hairline cracks are often found on the friction surface of the brake discs Hairline cracks up to a length of 10 mm do not present a technical problem and do not justify a renewal of brake discs Brake discs
108. ston in the caliper housing with piston resetting appliance a Use blocks of wood or similar b to keep the other pistons in place Also place a piece of wood c against the resetting tool to prevent the piston from being damaged when it is forced out N47 0216 4 Brembo brake calipers 18 93 WO Audi A8 2003 gt Au Brake system Edition 03 2013 Remove seal using removal wedge 3409 When removing ensure that the bore of the cylinder is not dam aged Installing The surface of the piston and seal should be cleaned using only methylated spirits and then dried Apply a thin coat of lithium grease G 052 150 A2 to piston and seal before inserting Insert the seal into the brake caliper housing Fit protective cap onto piston Push piston into caliper housing exerting even pressure The protective cap must fit securely in the groove if necessary apply additional pressure with piston resetting appliance Note Brake line connection at brake pipe 12 Nm Brake pipe in brake caliper 19 Nm AN Caution Before driving vehicle for the first time make sure function of brakes is OK 94 Rep gr 47 Brakes hydraulics N47 0219 N47 0220 Sapa Audi A8 2003 gt C 0 Brake system Edition 03 2013 Auer 5 Brake caliper ceramic brakes a Note Brake line connection at brake pipe 12 Nm Brake pipe in brake caliper 19 Nm 5 1 Ser
109. t COD Brake system Edition 03 2013 Auer Display on VAS 505x The prompt to enter a display group appears in display zone Display zone 2 shows a keypad Enter 06 or O06 as display group number via the keypad 2 and confirm entry with Q key Fit wheels gt Wheels and tyres Repair group 44 AN Caution On vehicles with ceramic brakes the wheel must not be allowed to drop onto the brake disc This would cause irreparable dam age to the disc Screw two assembly pins into the wheel bolt holes when removing and fitting a wheel Insert the long as sembly pin into the top hole Check brake fluid level and top up if necessary Note The electronic parking brake must now be recalibrated Requirements Electronic parking brake must be released Selector lever must be in position P Switch off ignition take out ignition key and lock steering Recalibration will now be performed The electronic parking brake retracts and closes again audi bly It then sets the required clearance automatically Wait for this process to be completed Recalibration is now completed Then erase fault memory AN Caution After installing the brake pads and before driving the vehicle depress brake pedal firmly several times with the vehicle sta tionary so that the brake pads are properly seated in their normal operating position A Caution Be
110. t Rep gr 43 Operation of air suspen sion Raise the vehicle Remove wheels AN Caution On vehicles with ceramic brakes the wheel must not be allowed to drop onto the brake disc This would cause irreparable dam age to the disc Screw two assembly pins into the wheel bolt holes when removing and fitting a wheel Insert the long as sembly pin into the top hole Connect vehicle diagnostic testing and information system VAS 505x and diagnosis lead 3m with voltage supply VAS 5051 1 to 16 pin diagnostic connector of vehicle and select parking brake with address word 53 When doing this the ignition must be off a Note Ignition on Release parking brake Coding checked and rectified if necessary gt gt Event memory interrogated indicated faults eliminated and memory erased Display on VAS 505x Select function 53 Parking brake Select function 04 Basic setting Display on VAS 505x The prompt to enter a display group appears in display zone Display zone 2 shows a keypad When installing new brake pads LNEnter 05 or 005 as Display grouppnumber in display zone 2 via the keypad and confirm entry with Q key resetting piston When re installing old brake pads Enter 07 or 007 as Display group number via the key pad 2 and confirm entry with the Q key Brake opens all the wa
111. the brake caliper housing 98 Rep gr 47 Brakes hydraulics eee Audi A8 2003 gt COG Brake system Edition 03 2013 Auer Fit protective cap onto piston N47 0219 Push piston into caliper housing exerting even pressure The protective cap must fit securely in the groove if necessary apply additional pressure with piston resetting appliance Note Brake pipe in brake caliper 19 Nm Brake line connection at brake pipe 12 Nm AN Caution Before driving vehicle for the first time make sure function of brakes is OK 5 Brake caliper ceramic brakes 99 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 6 Rear brake calipers for electronic parking brake and handbrake EPB 6 1 Servicing brake calipers Applies to steel and ceramic brakes Note When carrying out repairs install all parts supplied in repair kit Apply a thin coat of assembly paste to brake cylinder piston and seal 1 Self locking bolt Q Tightening torque 35 Nm Q Always renew Q Counter hold guide pin when loosening and tightening 2 Brake caliper with actuator Q The brake caliper should not be separated from the actuator Q After repairing pre bleed brake caliper housing gt page 110 3 Bleeder valve 4 Dust cap Fit onto bleeder valve 5 Seal Removing and installing gt page 101 6 Compressor nut QO To operate the parkin
112. the pedal travel will be in creased as a result AN Caution After installing the brake pads and before driving the vehicle depress brake pedal firmly several times with the vehicle sta tionary so that the brake pads are properly seated in their normal operating position Check brake fluid levePandtop up if necessary AN Caution Before driving vehicle for the first time make sure function of brakes is OK 44 Rep gr 46 Brakes mechanism meee Audi A8 2003 gt C 0 Brake system Edition 03 2013 Auer 1 3 Renewing brake caliper Removing Note Mark brake pads when removing them if they are to be rein Stalled Reinstall in their original position to prevent uneven braking When installing brake discs note direction of travel indicated by arrow on brake disc and fitting location left or right Raise the vehicle Remove wheels Secure brake disc with one wheel bolt see arrow Remove brake pads gt page 41 Installing Installation is carried out in reverse sequence Install brake pads gt page 41 Bleed brake system gt page 110 Fit wheels gt ELSA Wheel Tyre Guide gt Rep gr 44 AN Caution After installing the brake pads and before driving the vehicle depress brake pedal firmly several times with the vehicle sta tionary so that the brake pads are properly seated in their normal operating position Check br
113. vicing brake caliper ceramic brakes 1 Bolts for brake caliper a Note These bolts do not have ened in order to remove caliper or change the bia Q Tightening torque 190 Nm 2 Retaining spring for brake pads 3 Guide pin 4 Brake caliper QO If assembly work is re quired do not leave cal iper hanging from brake hose but secure it to body with wire Q With the exception of Removing and instal ling brake pads Re moving and installing brake caliper and Re moving and installing brake pistons no re pairs may be performed on the brake caliper Q Do not twist hose when installing 7 A i al Q Allocation gt page 1 s rl pz 3 2465 10143 5 Brake caliper ceramic brakes 95 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 Brakes 5 Brake pads QO Wear limit gt page 1 Note A wire for the wear indicator is fitted to the inner pad There is an adhesive foil on the backplates of the outer brake pads Remove the protective foil before fitting pads Before fitting pads clean guide surfaces and apply a thin coating of polycarbamide grease gt Parts catalogue Different versions available gt Parts catalogue Always renew on both sides of axle Removing and installing Q Checking pad thickness gt Maintenance Booklet 4E 10 Ribbed bolt Q Tightening torque 190 Nm Q Clean ribs if using again COO vo O0 11 Brake car
114. ving Note Ignition on Release parking brake Coding checked and rectified if necessary Event memory interrogated indicated faults eliminated and memory erased gnition off Select jacking mode gt Rep gr 43 Raise the vehicle Remove wheels Note gnition must be switched offat least 30 sec before unplugging connector Clean whole area around connector and actuator motor brake caliper Press down securing lug on upper part of connector vehicle side of connection as shown in illustration detail and unplug actuator motor connection Pull connector on actuator side of connection out of the bracket A46 0316 80 Rep gr 46 Brakes mechanism Audi A8 2003 gt GANN Brake system Edition 03 2013 Auer Remove both securing bolts Torx TX25 from actuator motor Remove actuator motor Remove seal with suitable tool Make sure you do not damage annular groove for seal and con tact surface on actuator motor a Note Do not use tools with sharp edges If necessary clean annular groove and contact surfaces Only use brake cleaner Installing Fit new seal Back off adjuster screw on caliper slightly to facilitate installa tion of actuator motor Note This makes it easier to install the actuator motor 7 Overview of components electronic parking brake and handbrake EPB 8 1 COLD Audi A8 2
115. y the pad thickness does not have to be entered later on All vehicles 4 Rear brakes electronic parking brake and handbrake EPB 69 COLD Audi A8 2003 gt Au Brake system Edition 03 2013 Remove securing bolts from brake caliper housing when do ing this counter hold on guide pins Note Do not unplug connection of actuator motor and or brake system Push connector out of retainer Move brake caliper clear to one side Remove brake pads Remove guide clips Note It is possible to change the brake disc without removing the brake carrier Push back piston with piston resetting appliance T10145 Installing Steel version brakes Check the thickness of the brake disc when renewing the brake pads Refer to wear limit for brake disc Check brake disc for wear gt 1 Brakes wear limits page 1 Ceramic brakes The ceramic brake discs must always be checked for damage and wear when renewing the brake pads 2 Assessment of ceramic brake discs page 4 gt 3 Assessing degree of wear on ceramic brake discs page F All types of brakes continued Use only methylated spirits to clean the brake caliper housing Insert pad retaining springs rA 70 Rep gr 46 Brakes mechanism as ie Audi A8 2003 gt 444 Brake system Edition 03 2013 Aue Fit brake pads Ensure that the brake pads are located

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