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D2 - Axles, Brakes, Suspension and Steering Brakes, Springs, shocks, steering racks, steering columns, suspension arms, wheel hubs etc. |
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D2: Retrofit rear brake pads wear indicator system
I'll be retrofitting rear pads indicators next time I'll change brake pads.
I always thought that A8s should have brake pads wear indicators FOR ALL 4 WHEELS, not just the front ones -- these are QUATTRO cars after all ! The idea is that armoured A8 D2s came with rear brake pads with wear indicators. Because the same rear callipers were used in armoured and non-armoured vehicles (discs of different diameter but the same width of the discs and the same callipers), the brake pads will have the same geometry as in normal A8 cars, but will come with wear indicators. Physics: The heavier the car, the larger diameter discs were installed, so that braking pad grabs the disc with bigger leverage, farther from the disc centre, hence better braking efficiency at the cost of faster wear of the pads of course. This is why armoured cars came with wear indicators. There is retrofit electrical harness in corrugated conduit part number 4D4 971 261 that is designed to fit without having to solder anything. Plug and play into existing wear indicator harness in engine compartment. Connection point D55 in ELSA. There is existing male <--> female electrical connector at point D55. All you need to do is to disconnect that connector and connect harness 'into' the opening, so it'll look like legacy male <--> new female ------ new male <--> legacy female arrangement. Harness then goes to rear axle area under the car and connects to rear brake pads. Electrically all 4 sensors will be daisy chained and connected to the same "bulb" on instrument cluster. Costs: TPS quotes -- brake pads 4D0 698 451 E: £206.33 (available, but a bit eye watering), electrical harness 4D4 971 261: £53.20 (backorder from Germany). Pads are still available from eBay sellers (old dealer stock, etc). http://www.ebay.de/itm/Audi-S8-A8-4D...item3f2ad6852e http://www.ebay.de/itm/Audi-A8-4D-Br...item3cd43a1d70 http://www.ebay.de/itm/Satz-Bremsbel...item35c3eaef63 Because no one needs those brake pads they sit on shelves for years. I just purchased 4 (!) genuine sets from eBay for £50-80 each from UK and German sellers after some haggling -- (before publishing this post of course) Sellers think no one needs those pads, so they frequently appear at low cost. Just wait and grab them -- all good things come to those who wait. If there are people here who are seriously thinking of adding this feature let me know and I'll do a write up when I finish. Connection D55: Retrofit harness in a box: Male and female connection to D55 at the bottom of the picture, two connections to rear brake pads in the background:
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I'd rather drive on left Last edited by notorious; 18th November 2013 at 06:05 PM. |
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Cool.
FYI, D3's have wear indicator on the rear. The electronic handbrake measures the pad wear when it closes, eventually putting the brake pad wear indicator on the dash when the travel exeeds a threshold. Its about the only useful thing the electronic hand brake does....
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For parts enquiries and Forum User Administration please contact customer services directly, not me - enquiry@a8parts.co.uk, www.a8parts.co.uk, or call 01642 783537 The Daily Town Car - 2023 Tesla Model Y Performance. Black with Black. Giant ipad screen, huge sunroof, 4 wheel drive, Tow bar, lots of ooomph and made in China, so actually built properly unlike the Californian ones. The Family Wagon - 2018 Tesla Model X. Black, 7 Seats, Towbar, Homelink, Enhanced Auto pilot with Summon and self park, Heated front seats, CCS Charger upgrade, MCU2 Upgrade, Falconwing Doors, Self opening / closing doors, Netflix, Spotify, toys, Air suspension, alcantara roof + lots of other stuff...... The 17 year old Driver Wagon 2015 Skoda Citigo Monte Carlo. Alloys, Power steering, Aircon, Leccy windows, Sat Nav, bluetooth, central locking, cup holders, 59 whole bhp. Million times better than my first car. Well jealous..... The First 20 Audis: 2001 D2 4.2 QS Silver, 1997 D2 S8 Silver, 1999 D2 4.2 Silver, 2002 D2 S8 Dolphin Grey, 2003 C5 RS6 Blue, 1998 D2 S8 Black, 2000 D2 4.2 QS/S8 Ming Blue, 2003 D3 4.2 Ming Blue, 2005 B7 S4 Blue, 2006 D3 3.0 Tdi Black, 1999 D2 4.2 Silver, 2003 D3 4.2 LPG Crystal Blue, 2000 D2 S8 Silver, 2007 3.0 Tdi Q7 Black, 2009 B8 S4 Black, 1998 D2 S8 Agate Grey, 2006 D3 4.2 Tdi Blue, 2006 D3 S8, 2007 Q7 3.0 Tdi, 2006 C6 S6, The Second 20 Audis: 2011 A7 Sline, 2001 A2 1.4 Tdi Black, 2002 A2 1.4 Tdi Silver, 2006 A8 4.2 Tdi Blue, 2007 4.2 Tdi Q7, 2006 S4 Cab Silver, 2010 RS6 Saloon Black , 2007 TT Roadster, 2010 A8 D4 4.2 Silver, 2006 C6 A6 2.7 Tdi Quattro, 2000 D2 4.2 QS/S8 Ming Blue (again), 2008 Q7 4.2 Black, 2009 C6 RS6 Saloon Daytona Grey, 2001 Fully Loaded A2 Tdi, 2006 Avant S6 Black, 2007 VW Caravelle Exec Black (almost an Audi) 2009 TT Roadster Daytona, 2015 Q7 4.2 tdi lava grey, 2002 GmbH D2 demonstrator, 2006 D3 A8 LWB 4.2 Tdi Black Most Recent Audis: 2001 A2 1.4 Tdi Black, 2007 4.2 FSi Q7 ABT Blue, 2016 S5 Coupe Launch model, 2004 S4 B6 Cabriolet, 2016 Q7 Sline White, 2006 Q7 4.2 FSi Black, 2012 Q7 Sline+ 4.2Tdi White, 2008 Blue Audi S8 Everything Else 1989 Subaru Justy, 1986 Vauxhall Cartlton 2.0 GL, 1985 Vauxhall Carlton 2.2 CDi, 1987 Ford Sierra XR4x4, 1983 Vauxhall Senator, 1985 Vauxhall Senator 3.0i, 1997 Polo Saloon, 1997 Peugeot 306 1.9 TDi, Ford Sierra Sapphire 2000E, 1990 Subaru Justy, 2000 Subaru Impreza, 2000 Subaru Impreza RB5, 1993 Range Rover LSE, 2005 VW Bora, 2003 Skoda Superb, 2003 VW Passat V6 4 Motion, 1996 Peugeot 106, 2000 Range Rover 4.0, 2019 Tesla Model 3 Performance |
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Electronic handbrake is smth I'd like to avoid!
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I'd rather drive on left |
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another cool project
interesting about the bigger rear discs and caliper further out producing more breaking force. I'll keep that in mind as I was planning to upgrade fronts with RS4 calipers, but didnt want the hassle of installing RS4 rears. Maybe bigger discs on the rear is enough to match RS4 front brakes. |
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Hi Goran,
Here is the thread (http://as8.ru/forum/viewtopic.php?f=84&t=18998 -- it's in russian, but use google translate) on installing 310mm rear discs from armoured A8 with some pictures. The guy didn't want the hassle of RS4 install, so went this path with a couple of others. He had to use custom made bolts though, so it's not 100% OEM install. I personally think normal A8 rear callipers and pads look a bit 'sick' on such a large 310mm disc since not the full surface of the disc is utilised. I think it was Audi's 'makeshift' solution for an armoured vehicle. I DO LOVE thought the brake pad wear sensors part of the story .
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I'd rather drive on left Last edited by notorious; 18th November 2013 at 06:08 PM. |
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Today I managed to retrofit the rear pads wear indicator harness to my D2. It is relatively easy to do if you have a whole day.
The new retrofit harness is inserted into existing harness without having to cut any cables. All you need to do is to trace wire from the front wear indicator that merges with the ABS sensor wiring in a front wheel arch into a single 4 wire harness and then connects to the main car wiring via a 4 pin connector. All you do is disconnect that connector into parts A and B and then connect part A into part A of the harness and then part B into part B of the harness (see the first picture below with Y type of wiring with two connectors). The connectors can be found of both sides of the car so you will have a choice to run the wiring via the left or via the right side. I have chosen the right side as I had a spare slot in the clamps which hold the 3 fuel lines which run from the nose to the rear. The unused 4th slot was used for wiring. I also changed metal part of the clamps since they were too rusty on my car. They cost pennies. Pictures! The front side of the 'plug-and-play' connector which can of course be looped The full harness, about 5m. Just the right size. Rear wheel 1 connector Rear wheel 2 connector Old fuel lines clamp. Notice a spare slot from the left hand side of the picture Rusty clamps changed and the wiring fitted now (corrugated plastic pipe on the right) Connect the new harness to the rear pads wear indicator connector And hide the connector in the recess of the wheel arch
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I'd rather drive on left Last edited by notorious; 1st June 2015 at 10:51 PM. |
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