1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Brembos On

Discussion in 'A3/S3 Forum (8L Chassis)' started by Pat, Oct 6, 2007.

  1. Pat
    Offline

    Pat Member

    Joined:
    Dec 20, 2006
    Messages:
    516
    Likes Received:
    0
    [Oct 6, 2007]
    Well finally fitted my Brembo GT kit today... We bled the system about 4 times.. but still have alot of pedal travel.. I`m guessing there is air in abs pump somewhere... Stll a far improvement..

    Quick question.. what pad does the GT Jrn Kit use?? Is it the same at the leon LCR!!
    #1
  2. Ads

    Ads

    [Sep 16, 2014]

  3. jojo
    Online

    jojo S3 Drift King! Staff Member Moderator

    Joined:
    Sep 4, 2003
    Messages:
    26,132
    Likes Received:
    1,641
    [Oct 6, 2007]
    Yup. :icon_thumright:
    #2
  4. Dave_Bayern
    Offline

    Dave_Bayern Slipping at 3.5Krpm

    Joined:
    Sep 26, 2006
    Messages:
    1,914
    Likes Received:
    4
    [Oct 6, 2007]
    Do you know what size master cylinder you have? And what size the pistons are in the Brembo kit?

    You are going to have a long pedal travel as I guarantee they are mis-matched, the standard Audi Master Cylinder isnt big enough to produce sharp pedal feel with Brembos.
    #3
  5. s3ollie
    Offline

    s3ollie Member

    Joined:
    Jan 2, 2007
    Messages:
    762
    Likes Received:
    7
    [Oct 6, 2007]
    Looking at you post on bleeding - you will need to bleed the master Cylinder if you haven't and cycling the ABS pump is only required if it has run totally dry
    #4
  6. Pat
    Offline

    Pat Member

    Joined:
    Dec 20, 2006
    Messages:
    516
    Likes Received:
    0
    [Oct 6, 2007]
    I didn`t do the abs but may try that tomoz.. I totally forgot about the master cyd... thought about it this morning and when it came to it i didn`t think about it..
    #5
  7. s3ollie
    Offline

    s3ollie Member

    Joined:
    Jan 2, 2007
    Messages:
    762
    Likes Received:
    7
    [Oct 6, 2007]
    i bled my ABS today and it didn't seem to make any difference
    #6
  8. s3ollie
    Offline

    s3ollie Member

    Joined:
    Jan 2, 2007
    Messages:
    762
    Likes Received:
    7
    [Oct 6, 2007]
    when i changed my calipers i didn't know about doing the MC and spent ages bleeding only to have no pedal. soon as i found out i had to do it a few bubbles came out and it was fine. bit of a pain to get to though
    #7
  9. Pat
    Offline

    Pat Member

    Joined:
    Dec 20, 2006
    Messages:
    516
    Likes Received:
    0
    [Oct 6, 2007]
    Where exactly is it?? Under the MC?? Its bad enough getting fluid in there let alone trying to bleed.. any suggestions??
    #8
  10. jojo
    Online

    jojo S3 Drift King! Staff Member Moderator

    Joined:
    Sep 4, 2003
    Messages:
    26,132
    Likes Received:
    1,641
  11. s3ollie
    Offline

    s3ollie Member

    Joined:
    Jan 2, 2007
    Messages:
    762
    Likes Received:
    7
    [Oct 6, 2007]
    you need to take the boost pipe off or disconnect the front joint and clamps and put the pipe to the side. then theres two nipples on the side of the master cylinder, both need to be bled.
    I opened the nipple with a long socket, put a pipe on then would clamp the pipe with grips instead of closing the nipple on each depression of the pedal to stop the fluid going back in, because its near impossible to get a spanner in there to close the valve.

    obviously thats if you do it the pump the pedal way!

    my pedal was going flat to the floor before i did this though
    #10
  12. Dave_Bayern
    Offline

    Dave_Bayern Slipping at 3.5Krpm

    Joined:
    Sep 26, 2006
    Messages:
    1,914
    Likes Received:
    4
    [Oct 7, 2007]
    No-one has yet mentioned that the Audi brake system needs to be under pressure when bleeding then? and that an EZ-Bleed doesnt provide the required pressure.

    You'd be best off taking it to a specialist for bleeding, a one that has the correct VAG bleeding machine.

    Once thats done, you'll still find that the pedal travel is more than the OEM setup, if you want OEM pedal travel AND better stopping power then you need a bigger master cylinder.

    If you work out surface area/pressure the absolute best 4 pot brakes for the S3 are Boxster fronts, these are also better than the red ones as they are monobloc, lighter AND stiffer.
    #11
  13. simch
    Offline

    simch Active Member

    Joined:
    Feb 22, 2004
    Messages:
    2,028
    Likes Received:
    1
    [Oct 7, 2007]
    Not true. Mine are fine, very solid pedal.

    The problem here is the very well known and well documented bleeding problem. You need vagcom to do it properly, and whilst at it you may as well change the fluid too. Air gets trapped in the abs pump and master cylinder. They are a pig!!!

    What year and type of car do you have? What were the brakes like before. was the pedal ok? I only ask as there was a recall on some of the vacuum hoses for some of the c. 2000 cars. But I think they have all been covered now!
    #12
  14. voorhees
    Offline

    voorhees Moderator Staff Member Moderator

    Joined:
    Dec 18, 2005
    Messages:
    15,103
    Likes Received:
    1,180
    [Oct 7, 2007]
    mine ok as well
    #13
  15. Dave_Bayern
    Offline

    Dave_Bayern Slipping at 3.5Krpm

    Joined:
    Sep 26, 2006
    Messages:
    1,914
    Likes Received:
    4
    [Oct 7, 2007]
    Not true?

    So how do you explain the physics?

    Lets start from scratch here. I'll round up or down to avoid mutiple decimal points.

    The S3 has 54mm pistons on a sliding caliper design as standard.

    So, its 3.142x27x27x2 = 4581 sq mm

    The Brembo GT caipers are the Family A 2 piece. I'm not 100% on the piston size as I dont have a set here but they are supposed to be 36 & 44mm pistons if they are the Big Red variety.

    3.142x18x22x4 = 4976 mm sq.

    So, the big reds have 400 sq mm more surface area than the standard pistons that need pushing out to engage the discs.

    Increasing the piston size will increase power but require longer pedal travel, so ALL Brembo kits have longer pedal travel than OEM. And the OEM pedal travel is atrocious.

    Increasing the master cylinder bore size will reduce power but give a firmer feel to the pedal, so ideally, you want to increase both, master cylinder and piston size.

    Now, the larger discs of the Brembo system mean you get greater stopping power due to rolling intertia being at the outside of a larger disc and the pads being larger than standard pads.

    This still means pedal travel is increased, regardless of better stopping power.

    However, as an aside, and tackling the original issue, I had pedal travel/ABS problems when I had a leaking N75 hose, the Audi brakes work on a vacuum sytem that is part of the intake air system, for example, try pressing on the brake whilst at full boost, you cannot.

    So it could be worth checking your vacuum hoses on the intake side?
    #14
  16. madvw
    Offline

    madvw Active Member

    Joined:
    Jul 26, 2005
    Messages:
    2,488
    Likes Received:
    2
    [Oct 7, 2007]
    Brembo GT's aren't big reds though are they? Most people refer to big reds as porsche calipers.

    If the brembo GT's are the same as the leon cupra R's, then you get a slightly longer pedal travel, but better sustained breaking. You will always get a slightly longer pedal travel as said as they have a larger capacity.

    Increasing the capacity of the MC isn't required though, unless you want to, as the MC capacity of the LCR is the same as that of the S3.
    #15
  17. jojo
    Online

    jojo S3 Drift King! Staff Member Moderator

    Joined:
    Sep 4, 2003
    Messages:
    26,132
    Likes Received:
    1,641
    [Oct 7, 2007]
    I honestly can't feel much of a difference in pedal length between standard S3 and Brembo GT setup, I only know the standard S3 items were not bad, but didn't cope with remapped power very well, the Brembo set up is a much better arrangement.
    #16
  18. Dave_Bayern
    Offline

    Dave_Bayern Slipping at 3.5Krpm

    Joined:
    Sep 26, 2006
    Messages:
    1,914
    Likes Received:
    4
    [Oct 7, 2007]
    Leon Cupra R calipers are big red calipers yes.

    Well, they might as well be the same, they have the same piston sizes, same two piece construction and are both made by Brembo.

    However, people seem to think they are doing an all round upgrade when fitting the Brembo kit, this isnt correct, you are upgrading your braking capability but you will suffer as a result.

    Pedal travel is longer and discs cost more.

    What I can't fathom is why people are so obsessed with the red calipers.

    Brembo/Porsche Boxster front calipers have better matched piston sizes, are monobloc (stiffer and therefore perform better and weigh less.

    Yet people still buy the Brembo GT kits!

    There is a reaosn Porsche stopped using them, the last production car they had them on was 1995 or something!!

    All modern Porsches uses monobloc design now, yet the Audi/VW world havent caught on.
    #17
  19. simch
    Offline

    simch Active Member

    Joined:
    Feb 22, 2004
    Messages:
    2,028
    Likes Received:
    1
    [Oct 7, 2007]
    Brembo gt calipers are different to the "big reds" a la 928 etc.
    S3 mc and lcr mc are the same.

    My s3 on stock brakes was ****.
    My car on brembos is ok, even with 350hp.

    Brembo gt kit comes with braided lines which help pedal travel a tad. However they work, they work. And for less than £800 all in fitted, they are a bargain!

    Dave, for someone without an s3 or brembos, you sure do know a lot!!!
    #18
  20. mintie
    Offline

    mintie Member

    Joined:
    Jun 26, 2006
    Messages:
    154
    Likes Received:
    0
    [Oct 8, 2007]
    Didnt your brakes fail you on your last outing to CC .I think if I remember you had two near misses 1 on the service road and 2 on the track.
    Only ever put MINTEX fast road pads in my S3 and I have never had any sort of failures, yes they do smoke a little but dont all brakes do this when being worked hard on a track.
    #19
  21. jcs356
    Online

    jcs356 Brum brum

    Joined:
    Jun 14, 2004
    Messages:
    2,684
    Likes Received:
    36
    [Oct 8, 2007]
    I'm glad I paid a mate to fit mine who had all the necessary pressure bleeding kit!

    In terms of the setup, no complaints from me when compared to standard.
    #20
  22. jcb
    Offline

    jcb Active Member VCDS Map User

    Joined:
    Sep 19, 2005
    Messages:
    4,118
    Likes Received:
    13
    [Oct 8, 2007]
    cupra brembos are NOT "big reds".
    "Big Reds" are generally regarded as the brembo four pots from the 993 chassis porsches. They are not monobloc and suffer from the same issues that the brakes on the RS2 and earlier S4's...namely the plate between pad and piston gets corrosion under it and causes the pad to move in and seize if left.
    The Boxster and 996 chassis Porsche Brembos are monobloc and don't have this problem and are often referred to as "big reds" although this is incorrect

    The Junior GT kit is closer to the Cupra
    http://www.performancealloys.com/images/suspension_pics/GT-Junior-Kit-Crossdrilled.jpg
    Calipers on a Cupra - note studs bolting caliper together
    http://www.drivertuition.com/images/ap3.jpg


    These are the original "Big Reds" non monobloc 993 chassis equivalent Brembos, the have a rounder moulding to the caliper, no through bolt and the twisted wire spring retainer clip
    http://www.zeckhausen.com/images/brake_install/BMW/E39/Movit/front/12t_Install_Caliper.jpg
    http://www.rtm-racing.be/2005/sales/racingequipment/image078.jpg

    These are the monobloc Boxter,996 chassis equivalent, note more angular caliper design and flat pad retainer
    http://www.audipages.com/upgrades/bira8.JPG

    you will get more travel, whether it is noticable or not once you replace with decent fluid and braided hoses is down to individuals.
    #21
  23. Dave_Bayern
    Offline

    Dave_Bayern Slipping at 3.5Krpm

    Joined:
    Sep 26, 2006
    Messages:
    1,914
    Likes Received:
    4
    [Oct 8, 2007]
    Its piston size I was referring to, and two piece design, big reds in similarity to Cupra R calipers.

    I even mentioned it a couple of posts up.

    However, I'll shut up now, everyone seems to think they made the right choice buying them and doesnt like to be told otherwise, despite Porsche rubbishing the two piece design ten years ago. For a good reason.
    #22
  24. bantam1
    Offline

    bantam1 Member

    Joined:
    Aug 15, 2004
    Messages:
    527
    Likes Received:
    1
    [Oct 8, 2007]
    Same REAL WORLD experience here too. Brembos providing vast improvement over standard braking with little PERCEIVABLE difference in pedal feel.

    This forum really has turned into a playground in the last year or so - reading it less and less now. A pity.
    #23
  25. Ess_Three
    Offline

    Ess_Three Active Member

    Joined:
    Feb 19, 2001
    Messages:
    5,383
    Likes Received:
    6
    [Oct 8, 2007]
    Good info there! Cheers...
    #24
  26. Ess_Three
    Offline

    Ess_Three Active Member

    Joined:
    Feb 19, 2001
    Messages:
    5,383
    Likes Received:
    6
    [Oct 8, 2007]
    Let's be honest here...

    Brembos will give better ultimate stopping power. This is not in doubt.
    Any Brembos really...


    Brake feel is individual..I'm with Dave on this one. I went from Mk3 Golf callipers to S3/TT callipers (a 1mm or so difference in piston size and buggered my brake feel...so Dave has a point)

    I fitted Brembos to my S3 and the pedal travel was more...not so much as to bother me as the pedals were not great for heel-toeing, but longer non the less...and feel IS affected.
    All in all...I reckoned the Brembo Jr kit was a good upgrade...liveable increase in travel/decrease in feel for much better brakes.


    Porsche are known to lead the world in braking efficiency...and the move to monoblocks was through performance...as Dave suggested.
    He has a valid point...whether some like it or not.


    If you pose to the local wine bar, it's unlikely you will notice the lack of feel, increase in travel or any other of the negatives of huge Brembo based set-ups...but the same people are probably happy with the handling of he S3.
    To each, their own...

    To those who possibly drive a bit harder, or brake a bit harder, or do lots of trackdays...or those who have driven cars with impeccable brakes...the negatives of certain Brembo based kits will be enough to put you off, and seek out a 'better' solution.
    Again, to each their own...


    A shame that threads like this get criticised when good info is being posted...as it's a pleasant change to the usual LED washer jets / how fast will my big turbo S3 be / why is my big turbo S3 not as fast as I thought type of thread.
    Hell, it's even written in plain English...with no 'txt talk'.

    Bravo!!
    #25
  27. Ess_Three
    Offline

    Ess_Three Active Member

    Joined:
    Feb 19, 2001
    Messages:
    5,383
    Likes Received:
    6
    [Oct 8, 2007]
    Oh, and for the record, I've never needed a pressure bleeder either..not for my Brembos on my S3 or the brakes on my GTI...just a good old fashioned tube and bottle..and a VAG Com for cycling the ABS pump, if required.
    #26
  28. Pat
    Offline

    Pat Member

    Joined:
    Dec 20, 2006
    Messages:
    516
    Likes Received:
    0
    [Oct 8, 2007]

    Thats all we did was bleed them the old fashioned way just with a bottle.. Just think i need to run vag for the abs pump... Overall i`m happy with the upgrade.. A massive improvement so I`m happy
    #27
  29. Ess_Three
    Offline

    Ess_Three Active Member

    Joined:
    Feb 19, 2001
    Messages:
    5,383
    Likes Received:
    6
    [Oct 8, 2007]
    As long as you've done the master cylinder as well...a wee cycle of the ABS pump should see you alright.
    Mine came in perfectly, 1st time...on the Golf and the S3.
    #28
  30. jcb
    Offline

    jcb Active Member VCDS Map User

    Joined:
    Sep 19, 2005
    Messages:
    4,118
    Likes Received:
    13
    [Oct 8, 2007]
    porsche went monobloc because the "big reds" had a glaring design fault in the mixing of alloys/metals that easily corroded between the caliper, the piston face and the pad.
    binding and a few warranty cliams later.........
    #29
  31. Ess_Three
    Offline

    Ess_Three Active Member

    Joined:
    Feb 19, 2001
    Messages:
    5,383
    Likes Received:
    6
    [Oct 9, 2007]
    Although no doubt a factor, Porsche went monoblock for the same reason that the Bike makers went monoblock - stiffer and lighter.

    Less parts, so less parts to go wrong - as you say - but the reduction in unsprung weight and increase in performance combined with the technology being available to manufacture monoblocks easily with the far more difficult machining associated is no boubt also part of the reason behind the switch.
    #30
  32. HTC
    Offline

    HTC Active Member

    Joined:
    Jan 11, 2004
    Messages:
    3,413
    Likes Received:
    0
    [Oct 9, 2007]
    Sorry to hijack, but would people recommend cycling the ABS pump at the end of the bleeding sequence or first?
    #31
  33. Ess_Three
    Offline

    Ess_Three Active Member

    Joined:
    Feb 19, 2001
    Messages:
    5,383
    Likes Received:
    6
    [Oct 9, 2007]
    I've always bled the MS, then the callipers, then cycle the ABS pump, then a final bleed of the callipers again.
    That seems to work.
    #32
  34. jcb
    Offline

    jcb Active Member VCDS Map User

    Joined:
    Sep 19, 2005
    Messages:
    4,118
    Likes Received:
    13
    [Oct 9, 2007]
    not related but kind of........got a parcel today!
    [​IMG]


    360x34mm with Brembo four pots.....(monobloc!)
    #33

Share This Page