Announcement

Collapse
No announcement yet.

Hydraulic to Vaccum servo conversion

Collapse
This is a sticky topic.
X
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Hydraulic to Vaccum servo conversion

    I thought this would be of use to someone so here goes.

    After all the ordeal i had with the hydraulic system, i decided to switch to a vaccum assist servo on the rs2. This is a common conversion in the US, and here is the parts list.

    brake booster (4a0 612 107A)
    gasket for booster (431 612 193)
    clevis (893 721 213)
    clevis nut (n011 162 9)
    clevis pin (443 721 371 A)
    check valve (191 611 933 E)

    You also may need the 3b power steering hose from the pump to the steering rack, as it seems to be the only one that fits the LHD cars, otherwise it shouldnt be a problem on RHD cars at all with the hose already there.

    Next is the modification on the power steering pump itself, by removal of the springs and pistons that lie under the x2 marked plugs with the big cross, or X (depends the way you look at it!!)

    In addition, you need to modify the steering rack return hose, which is a simple return, no high pressure one, as well as there is a need of either a T joint or an additional hole to the Inlet manifold to get the vaccum from to the servo.

    Finally, the 2 cables on the hydraulic servo that are meant to measure the pressure in the system and light up the dash, can be left out, covered with tape or heat shrink, but do not hotwire them, as the alarm stays permanently ON.

    I enclose a small pdf description of the modification on an S4

    Hope it helps!
    Vasilis
    Attached Files
    Last edited by A80Avant; 25th September 2011, 20:19. Reason: title word addition

  • #2
    Thanks for posting this. I too think I will go vaccum on the avant.
    Eric

    95 S2 Avant under rebuild.

    Comment


    • #3
      done this on my RHD UrS6 for 2years.So far I'm happy with it.Thanks for your write up.
      one of a few I5 from Asia.

      Comment


      • #4
        no prob! i think it was missing from the forum anyway

        Comment


        • #5
          Stickified
          Cheers'en, AndyC

          K24 Racing - K24R Products

          sigpic

          Comment


          • #6
            Here is the part number for the LHD power steering hose required:

            893422893AE

            Comment


            • #7
              Hy Vas! I saw on your late pictures that u use different pas pump....
              I had no issues with mine after removing the pistons and plug the hole. What issues you had? Both pumps were damaged?
              Thank You!
              Eugen

              Comment


              • #8
                my second pump leaked on the lower of the 2 'X' marked seals, and the other garage should have used some loctite as well but hadnt.

                the 2nd pump although we modified the 2 plugs and used loctite, it didnt leak but was VERY noisy!!! it wasnt working properly at all! I dont know why as well, as when we removed that pump from my car originally it was absolutely fine.

                anyway, as we were ready to fit another dual vane pump which we would modify, we found a single pump laying around, and we thought it would be easier to make a bracket for it and use that rather than worry about leaks from the plugs. It was also 100bar spec and part number was 050145155A which was nicely situated in and didnt make any noises apart from the fact that it only whines a bit after the engine gets warm and only between a small rpm rise from 1300-1800rpm. Then i dont hear it anymore.

                I therefore found a second hand pump which i have sent for inspection and refurb to have aside in case i need to replace it. Otherwise the system works.

                I also noticed that the power steering hose is NLA and only ebay has one for 99euro+shipping and im thinking of getting one to have as a spare.

                I emailed audi tradition as well as they have one with AD ending on the part number instead of AE, and i think its the same hose.

                That way ill be ok if anything brakes down. I have been through a lot with these power steering issues, so much that i was thinking of using an electric steering rack at one point!!haha

                Comment


                • #9
                  so is this better than the normal sistem? more powerfull and reliable?
                  RED Mitsubishi Lancer Evolution VI TME nº 16 of 250
                  BLACK Mitsubishi Lancer Evolution VI TME nº 189 of 250
                  LWB Audi Sport Quattro project

                  Comment


                  • #10
                    powerful, i dont know, but certainly more reliable! no more faffing about brake bombs, and hydraylic fluids anywhere.. Just one pump for the steering, servo in place and if something brakes, a servo is dead cheap to replace and easy.

                    Im still waiting from Audi Germany to hear back from the hydraulic servo they sent me which was malfunctioning... I payed 750euros for it... i hope i get some money back.

                    Comment


                    • #11
                      Originally posted by A80Avant View Post
                      powerful, i dont know, but certainly more reliable! no more faffing about brake bombs, and hydraylic fluids anywhere.. Just one pump for the steering, servo in place and if something brakes, a servo is dead cheap to replace and easy.

                      Im still waiting from Audi Germany to hear back from the hydraulic servo they sent me which was malfunctioning... I payed 750euros for it... i hope i get some money back.
                      the "bomb" cost something like 800€ from AUDI,i asked for it 1 year ago....what a surprise

                      you said "some money back"? you should receive ALL money back¡¡

                      good luck and thanks
                      RED Mitsubishi Lancer Evolution VI TME nº 16 of 250
                      BLACK Mitsubishi Lancer Evolution VI TME nº 189 of 250
                      LWB Audi Sport Quattro project

                      Comment


                      • #12
                        Is it necessary to have that 4a0 612 107A brake booster, or is it possible to do it with 4A0612105P??

                        BK im not able to fin it in Ebay.....

                        Comment


                        • #13
                          im not sure, but i got those numbers from people that have done the change themselves.

                          others have gone for the A8 D2 brake servo. I cannot say which ones will work or not, im sorry. Only experience from others will show that.

                          A new brake servo from the audi shouldnt be that expensive anyway.

                          Comment


                          • #14
                            power steering pump used: 050145155A ZF

                            for this you can use the wheel of the ABY/ADU pump as it bolts on the above one, and you need to manufacture a bracket to hold the pump in place. Brian Tonks, did one for me within a few minutes, so not a big deal for those with welding capabilities. Put the 2 pumps side to side and its easy enough.

                            Comment


                            • #15
                              Audi A8 D2 vac serv is a massive lump. OK for LHD but may be a problem in RHD application.

                              Any servo such as A4 B6, B5, B3 should be fine.

                              Just did the pump mod as fitting an AAN to a B3.
                              Regards
                              Ryss
                              www.autostart.co.za

                              Comment

                              Working...
                              X