Announcement

Collapse
No announcement yet.

School me on HP2 brakes (please)

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • School me on HP2 brakes (please)

    None of the C4 UrS4/S6 sedans or avants that came to NAmerica (US and Canada) came with HP2 brakes (we only got Girling G60 front brakes). My "new" German-market 94 S4 V8 avant has HP2s. I was installing winter wheels and snow tires today and was looking at the calipers. I concluded that they are siginificantly different than anything I am familiar with (G60s, Boxster monobloc and Big Red/Black Porsche/Brembos (all of which, in that order, have been on my 93 UrS4 AAN sedan.)). For instance, I think I am seeing triple square socket head bolts (!!??). I did a quick search of the S2Forum for an HP2 Re and Re but found nothing (which is surprising to me). I did find some HP2 photos in Thuppu's UrS4 avant thread. But even then, I don't really understand how they work. As a result, I am looking to be "schooled" on HP2s.

    Here is some info (Thuppu's photo and info from my good friend, Kate, the friendly part person):



    Last edited by UrS4boy; 20 October 2014, 01:35.
    RS2'd 93 UrS4 5 spd sedan
    94 UrS4 V8 6 spd manual avant

  • #2
    I believe its the same brake that we pulled of an (12/99) a8l on the local junk yard today. Great upgrade for $50.
    Some B5 S4 had the same brakes. The bracket itself is in the caliper and the big surface help with the cooling.
    sigpic

    Comment


    • #3
      C4 HP2's are full iron, heavy ones. B5 HP2's are half alu and iron, like in my pic above. The offset is different between these calipers. Also the pads are different. HP2 is an floating caliper with the pistons on the other side only, just like many others OE calipers.

      I don't have any good pics, but maybe you can see the structure better from this pic..?

      Last edited by Thuppu; 12 December 2013, 08:50.

      Audi UrS4 Avant 2.5 20vt - twincharged - Project
      Audi 80q B4 Sedan 2.2 20vt - Daily user
      BMW 320d Touring e91 M-Sport - Daily user
      BMW 740iA e38 - Project

      Comment


      • #4
        Originally posted by varia View Post
        I believe its the same brake that we pulled of an (12/99) a8l on the local junk yard today. Great upgrade for $50. Some B5 S4 had the same brakes. The bracket itself is in the caliper and the big surface help with the cooling.
        The C4 HP2s do not fit on a G60-compatible NAmerican UrS4/S6 wheel bearing housing (aka strut). The 4A0615107/108 C4 UrS4/S6 calipers do not cross to the A8 or even to the S6plus. They are not the same as the B5 S4 HP2s either.
        RS2'd 93 UrS4 5 spd sedan
        94 UrS4 V8 6 spd manual avant

        Comment


        • #5
          Originally posted by Thuppu View Post
          C4 HP2's are full iron, heavy ones. B5 HP2's are half alu and iron, like in my pic above. The offset is different between these calipers. Also the pads are different. HP2 is an floating caliper with the pistons on the other side only, just like many others OE calipers. I don't have any good pics, but maybe you can see the structure better from this pic..?
          I saw that photo in one of your threads. I still don't understand if I need a triple square bit to remove the caliper or why I am seeing Torx screws near the pads.
          RS2'd 93 UrS4 5 spd sedan
          94 UrS4 V8 6 spd manual avant

          Comment


          • #6
            You only need to open the Torx's if you take the calipers apart. If you want to change the pads you don't need to open any bolt at all, just the metal wire brackets that hold the pads down(maybe there was a small screw that holds the braket fit, can't remember) To remove the caliper you just open the normal bolts that holds it on the strut.

            Not any of the HP2's are plug and play on the UFO strut. Some minor modifications is needed.



            Here is a good sticky of fitting C4 HP2's on UFO struts: http://www.s2forum.com/forum/showthread.php?t=49445
            Last edited by Thuppu; 12 December 2013, 09:26.

            Audi UrS4 Avant 2.5 20vt - twincharged - Project
            Audi 80q B4 Sedan 2.2 20vt - Daily user
            BMW 320d Touring e91 M-Sport - Daily user
            BMW 740iA e38 - Project

            Comment


            • #7
              Okay. I think I am starting to understand HP2 brakes better.

              I found this post regarding changing the pads (written by a girl so she must know about changing pads ):

              http://www.audiworld.com/tech/wheel39.shtml



              And then there are these photos from an upgrading post (HP2 to AP Racing) http://www.audiworld.com/tech/wheel12.shtml

              Removing the HP2 caliper the wrong way:



              Removing the HP2 caliper the right way:



              I guess I thought that the carrier was a separate piece, not integral with the caliper. Two bolts. I can handle that.
              RS2'd 93 UrS4 5 spd sedan
              94 UrS4 V8 6 spd manual avant

              Comment


              • #8
                here is the one from the a8

                sigpic

                Comment


                • #9
                  Originally posted by varia View Post
                  here is the one from the a8
                  Thanks. Unfortunately, the calipers being black and the lighting dark, I can't see what you want me to see.
                  RS2'd 93 UrS4 5 spd sedan
                  94 UrS4 V8 6 spd manual avant

                  Comment


                  • #10
                    My hp2 s are different to the photos above. No springs
                    My calipers have 2 inner pads which are held in the pistons. The outer pads are held in by 2 torxs.

                    I will at my brakes this week so will take some photos.

                    There is also a difference on the carrier part if 314mm discs to 323mm. The mounting holes are in a different position.
                    Audi A6 AEL 5cyl Quattro breaking.
                    Audi A5 3.0tdi Quattro Stage 2
                    07947385043

                    Comment


                    • #11
                      Originally posted by K7ERG View Post
                      My hp2 s are different to the photos above. No springs
                      My calipers have 2 inner pads which are held in the pistons. The outer pads are held in by 2 torxs. I will at my brakes this week so will take some photos. There is also a difference on the carrier part if 314mm discs to 323mm. The mounting holes are in a different position.
                      Thanks Craig. Sounds more like what I have on the C4 S4 V8 avant. Photos? Yes, please!!
                      RS2'd 93 UrS4 5 spd sedan
                      94 UrS4 V8 6 spd manual avant

                      Comment


                      • #12
                        Originally posted by K7ERG View Post
                        My hp2 s are different to the photos above. No springs
                        My calipers have 2 inner pads which are held in the pistons. The outer pads are held in by 2 torxs. I will at my brakes this week so will take some photos. There is also a difference on the carrier part if 314mm discs to 323mm. The mounting holes are in a different position.
                        Craig: Did you ever take any photos?
                        RS2'd 93 UrS4 5 spd sedan
                        94 UrS4 V8 6 spd manual avant

                        Comment


                        • #13
                          To complicate things - as I understand them anyway - there are multiple variants of the HP2 caliper. The one I am familiar with is on the C5 allroad with two Pistons and four little pads. This is the Girling/Lucas/TRW variant with the big spring clip that retains the pads.

                          The other type is referred to as the Pagid caliper by outlets in the UK at least - it has two pads and is different in several ways.

                          The 4-pad version is typical VAG floating design on lubricated pins. I just replaced one at the weekend as one of the Pistons was seizing up - not bad for 13yrs and 180k miles service. There are rebuild kits available but the price of refurbished caliper is about gbp160 so it wasn't worth it for me to take a voyage of discovery on such a rebuild.
                          Paul Nugent
                          Webmaster http://S2central.net
                          Administrator http://S2forum.com

                          1994 S2 Coupe ABY - aka Project Lazarus
                          2001 A6 allroad 2.5TDi - family tank
                          2003 S4 Avant 4.2 V8 - daily burble

                          Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

                          There are only 10 kinds of people that understand binary - those that do, and those that don't

                          Comment


                          • #14
                            I don't think the 2-pad version is a HP2 caliper, propably just a normal design floating caliper..? There is at least two different types of HP2's with 4-pads, as have came up in this thread. The pads are different between these two versions, so not switchable.

                            Audi UrS4 Avant 2.5 20vt - twincharged - Project
                            Audi 80q B4 Sedan 2.2 20vt - Daily user
                            BMW 320d Touring e91 M-Sport - Daily user
                            BMW 740iA e38 - Project

                            Comment


                            • #15
                              [QUOTE= I found this post regarding changing the pads (written by a girl so she must know about changing pads )[/QUOTE]

                              Aye was sick then :....... "The bears can smell the menstration"

                              Comment

                              Working...
                              X