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The Definitive Brake Thread for 8L A3/S3 Owners(and other Golf4 Platform cars).

Discussion in 'A3/S3 Forum (8L Chassis)' started by jojo, May 18, 2010.

  1. Dani_B19
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    Dani_B19 Audi-sports own special child.

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    One broken off? Been bodged?g
  2. Golfer1991
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    Golfer1991 Member

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    No, they simply don't exist! Everything is perfect and nothing is broken or bodged!!
  3. phil miller
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    phil miller Member

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    ive found this on mk4s before, some aftermarket MC suppliers dont have the bleed nipples in them
  4. Golfer1991
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    Golfer1991 Member

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    mmhh strange, because the old owner of the car (which I know very good), bought the car new, and ALWAYS did all the maintenance and repairs by official Audi garages, so it's quite impossible that they put an aftermarket MC on the car (if they changed it in all these years!)

    Is there another way to bleed the MC?
  5. phil miller
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    phil miller Member

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    The only other way is to have someone slacken the brake pipes coming out of the mc, then press and hold the brake pedal on the floor, tighten the pipes then release the pedal, do that a few times and that should get the air out
  6. jojo
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    jojo S3 Drift King! Staff Member Moderator

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    My 99' model has.
  7. Prawn
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    Prawn My other car is a MINI!!!!

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    terrible idea Phil.

    Itd solve his problem, because he'd need a new master cylinder, but that's not what we're aiming for is it....

    pressing the pedal to the floor during bleeding on these cars almost always causes the MC seals to flip, meaning the mc needs to be removed and rebuilt/replaced.

    Vacuum or pressure bleeders only please!
  8. Sam_
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    Sam_ Down under

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    Last edited: Sep 24, 2012
  9. s3dave
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    s3dave TFSI Hybrid

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    Its no internet myth it does happen, ive had it done to me (non Audi) it is very easily done..it is caused by a ring that forms through normal operation then when the pedal travels further than the norm (sometimes years) it hits the ring/mark on the piston and the seals flip...
  10. Sam_
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    Sam_ Down under

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    What is the "ring" made up of though? Contaminates in the brake fluid? Why would they form there? I think you' have to be very very unlucky...
  11. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    i understood it was simply wear on the cylinder/piston forming a ridge at the end of its normal area of travel.

    I've never personally had a problem with full stroking the master cylinder, but i have heard of various people over the years on all makes of car killing the MC with that method of bleeding.
  12. MingeBlue
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    MingeBlue Member

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    Hi, I have a 2002 A3 1.8T sport, I need to replace front and rear discs and pads, I was looking at www.eurocarparts.com this morning for something else when I noticed its 31% off till the 30th Sept so I might as well get the parts now, but Im a bit confused on the front disks and pads I should get, questions are,

    1. They seem do two makes Pagid and Eicher which are the best to go for ?

    2. Each brand seems to have 2 different front disks for example Pagid has this one at £34.20 Pagid Audi | Euro Car Parts UK’s No.1 Car Parts Retailer and then this one at £40.20 Pagid Audi | Euro Car Parts UK’s No.1 Car Parts Retailer . What is the difference is it just quality ? Would either fit my car ?

    3. The front brake pads seems to come in 2 flavours one with an 'intergrated wear sensor' these appear to have a wire connector hanging off them Eicher Audi | Euro Car Parts UK’s No.1 Car Parts Retailer or others that say 'Excl wear warning contact' these are a bit cheaper Eicher Audi | Euro Car Parts UK’s No.1 Car Parts Retailer . Not sure what to order, my car should have that break pad warning light so do I need the pads with a wire hanging off ?

    4. Do I need to match up the disk and pads, by that I mean should a disc of size X have pads of size that fit this disk ?

    thanks
  13. Sam_
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    Sam_ Down under

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    Yeah it's strange. I took an NVQ (?) evening class on motor mechanics about 10 years ago at a local college where it wasn't mentioned and I've never come across it and bled quite a few cars using that method. I mentioned it to the local guy here I use for work I don't have space/tools to do, who worked at VW Racing, and he said he'd never come across it either. You must have to be really unlucky!
  14. s3dave
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    s3dave TFSI Hybrid

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    I think it is worse if you press the pedal down fast, if it is done slowly it seems to be ok.. but i would never use that method again..
  15. Prawn
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    Prawn My other car is a MINI!!!!

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    it's happened to me too, not through bleeding but through Jardo driving the car and abusing it.

    Known it happen to several others too. Brakes needing minor work like a hose changing, they've bled them the 'old' way, and the master has never bled up again and needed replacing.
  16. superkarl
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    superkarl MAN OF STEEL

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    only happens whent the MC runs dry. and its not just our cars.

    i do it the old way, so do lots of others. no problems if its done right
  17. jojo
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    jojo S3 Drift King! Staff Member Moderator

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    Your legs aint as strong as your arms are they? :superman:
  18. Golfer1991
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    Golfer1991 Member

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    mine is exactly like this:

    [​IMG]

    I've always used a Motive Power Bleeder to bleed the brakes, but after reading some posts telling about the incredible braking power of the Front Boxster 986 Calipers, I understood that something is wrong in my setup...
    I have this setup:

    Porsche Boxster 986 Front Calipers
    Pagid RS4-2 brake pads
    Zimmermann 312x25 discs
    ATE Super Blue fluid

    This setup shouldn't be so bad, and of course should make a lot of difference between the OEM setup, ma it's not like that!
    To have a little more braking power as OEM, I need to press the pedal near the end of the pedal travel and sometimes going down from the mountains streets (yes we have lots here in switzerland!:arco:) I feel like the brakes are not stopping the car well, but looks like they're more slipping away than braking!

    What should I try first?
  19. Sam_
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    Sam_ Down under

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    Yeah, I've never had it happen in 10 odd years so must be doing something right, or just lucky. Regardless, pressure bleeding is way easier.
  20. Grale1
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    Grale1 Member

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    Hi, I'm a little confused on reading this guid, I would like to upgrade my brakes so I would go to the 312mm, reading the guid at the start it looks to me there is no difference in the calipers to the standard ones on my a3 1.8t AGU
  21. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    nope, calipers are the same, you just change the carrier to move it out to take the larger disk.
  22. Grale1
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    Grale1 Member

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    Ok cool, so ill just hunt down some bigger carriers then, and the discs needed
  23. AFDanHef
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    AFDanHef Member

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    I finally found and bought a pair of Porsche calipers that I like.

    I've been researching the Alfa Romeo, Brera 330mm disc and noticed that the centering diameter on the Alfa disc is bigger than the Audi S3 disc center by 5 mm. The Alfa center hole is 70mm and the S3 is 65mm. This seems to me like it would be a problem. Doesn't the disc ride or is kept in place by the hub center. If there is space around the hub center won't this allow some play and eventually cause the disc to fail?

    Maybe I'm just being paranoid. Frenchman, have you had any problem with this? Or anyone else who has used these disc for the bigger upgrade?

    Here's links to the dimensions from the Brembo website.

    Brembo | Aftermarket Catalogue

    Brembo | Aftermarket Catalogue
  24. AFDanHef
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    AFDanHef Member

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    I finished installing my the Porsche brakes with Alfa 330mm disc today and I think the 70mm center hole on the 65mm hub is a problem. After I drove them around for a few minutes I heard something rubbing. I took a good look and it looks like the disc shifted and is rubbing on the calliper. :ermm:

    I was wondering if anyone else with this setup had this problem?
  25. 16Klappe
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    16Klappe Princess Slayer

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    I didn't abuse it :( I just drove it without any brake fluid :(
  26. jojo
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    jojo S3 Drift King! Staff Member Moderator

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    Custom spigot/centering rings will sort this out.
  27. vrbob
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    vrbob Thats no Moon, Thats a space station!

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  28. AFDanHef
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    AFDanHef Member

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    I had some custom centering rings made out of nylon and they work great to center the disc but that wasn't what was rubbing. I took everything apart and inspected really well. The disc is clearing the caliper by a couple of millimetres around the outside.

    I tried to bend and shape the original dust/heat shield so that it could still be used but on full lock it was getting smashed between the disc and the lower control arm. So I just removed the dust/heat shield and everything works perfectly!!
  29. vrbob
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    vrbob Thats no Moon, Thats a space station!

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    Can someone point me in the right direction for a guide to bedding in new brakes please.

    As i am going to be fitting an upgrade to my car in the near future which has the ferodo DS2500 pads fitted and i remember reading that these need bedding in in a specific way to make them work best. The pads and discs are both new so does this also have to be taken into account with the bedding in process?

    Someone also had a guide (maybe from Bill at B5?) on the whole process so if there is also a link to that someone can post up that would be very useful.

    Cheers
  30. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    Brake Fitting questions-Bedding in DS2500's advise - SEAT Cupra.net - SEAT Forum

    <tuffty/>
    vrbob likes this.
  31. 16Klappe
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    16Klappe Princess Slayer

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    Do full on as hard as you can stops from 70/80mph to walking pace.

    You should be looking to repeat that process until the pads stink and are smoking. Which on road pads is usually 4/5 cycles and on race pads more like 10/15 cycles.

    Then drive the car for as long as possible without braking to allow them to fully cool.

    If you were able to view the discs during this process you would see pad material transfer to the discs and the color change from bright silver with a criss cross pattern from machining to a light grey surface with concentric scoring rings on the discs.

    The aim of "bedding in" brakes is to transfer a layer of adherent pad material to the discs which allows them to perform at their best in an even and controlled way. You need to heat the pads to the point of them transferring material onto the discs. There is a chemical and a physical element to brake discs and pads, they need to work in both ways to offer full performance.

    If you just gently touch the brakes and take it easy the pads will remain in an abrasive state and will just score the discs, resulting in a **** brake for the life of the discs and pads.
  32. Alex C
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    Alex C Well-Known Member

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    what happens if you dont do the bedding in process straight away? Can you bed them in later?
  33. vrbob
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    vrbob Thats no Moon, Thats a space station!

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    Thanks for the quick replies i will have a read through that link :)
  34. vrbob
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    vrbob Thats no Moon, Thats a space station!

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    Thats interesting didtnt know it was to transfer material i just thought it was to mate the 2 surfaces properly.

    Is it needed to do the 70-80-mph stuff straight away? as i would have to get to the motorway on a quiet night in order to pull that off safely.

    *edit* so after quick read of the link above this is what bill says :
    Bedding in DS2500's
    Ideally new disks & pads @ same time.
    1) Drive to 40-50mph and lightly brake to a near stop 3 times and continue driving for a few minutes to allow air to cool..

    2) Drive to 40-50mph and slight more pedal pressure & brake to a near stop 3 times and continue driving for a few minutes to allow air to cool..

    3) Drive to 60-70mph and brake heavily with high pedal pressure & brake to a near stop 3 times and continue driving for a few minutes to allow air to cool..

    after diring it about, stop and inspect disks for an even wear on the surface. They me be smoking after the 3rd stage, ideally you should drive around so they can cool down.

    If the disk face is still looking uneven wear, then repeat the above one more time.

    job done.
    [​IMG]

    so better to do a few slower stops before doing a higher speed one
  35. 16Klappe
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    16Klappe Princess Slayer

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    Bills bedding in process is the same as mine, but he changes the speeds to make it seem like he knows what he's talking about as though it makes a difference :p There is a potential safety element to having a quick stab at a lower speed before going up to 70/80, but it doesn't need to be as technical as 3 stops at x speed followed by 3 stops at y speed both ending in z speed / the number of feet travelled per second.

    Basically murder them, regardless of how you don't.

    It's fine to do a couple of miles on them before bedding in, but the longer you are driving them without them bedding in them the more material you are wasting by braking abrasion.

    Brakes can be rejuvenated by giving them a beasting, but they are never as good as if they have been started off right when the pad is fresh, clean and at its softest cold state before to many heat cycles. This is its most receptive time for bedding in before it gets hard.
  36. vrbob
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    vrbob Thats no Moon, Thats a space station!

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    So treat em mean keep em keen is the phrase of the day for bedding in brakes then :)
  37. vrbob
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    vrbob Thats no Moon, Thats a space station!

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    Okey Doke,

    First off i am going to be fitting 4pot calipers and i managed to find a guide from the manufacturer of the calipers (AP CP6600`s) that explains the orientation of the calipers depending on wether they are fitted in a trailing (behind the disc) or leading (infront of the disc) manner. According to the guide each caliper is handed eg left and right so have worked that out by the part number. Secondly as the pistons are slightly different sized the smaller piston should see the first rotation of the disc as this ensures the amount of taper is minimal during their service life. So i have taken the off the pipes and nipples and swapped them around to suit a leading setup (how the S3 is setup).

    My next question is in regards to grooved discs as i can see they are also left and right handed but dont know which is what so which way should the grooves be orientated? eg if i am looking at the drivers side of the car should the grooves lean backwards or forwards on the disc?
  38. Sam_
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    Sam_ Down under

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    I'm pretty sure Tuffty is running those calipers (TVR ones)
  39. vrbob
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    vrbob Thats no Moon, Thats a space station!

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    Yup :)

    Managed to source a proper bargain and scored calipers the same TVR ones as tuffty (basically unused) new DS2500 pads, new grooved discs, some braided lines and a pair of Badger 5 custom hangers all in one hit and got the lot for £525 delivered :)

    So ordered some ATE Blue fluid and sourced a couple of anti rattle clips as these were the only missing part and should be ready to rock and roll soon on my new brakes hence my lots of questions lol
  40. Il Signor Zetec
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    Il Signor Zetec New Member

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    I have the same problem, but if I turn all the wheels, the discs touch with the dust cover and with hub! Only me and you had this problem with this setup???

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