Announcement

Collapse
No announcement yet.

Brake bomb replacement

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

  • Brake bomb replacement

    I had a strange issue develop overnight whilst the car was parked up in the garage. The pas reservoir overflowed all by itself
    Now I'm thinking this can only be because of a faulty bomb? The brake warning buzzer occasionally sounds if the car hasn't been used in a while for a few seconds on start up.
    So, I removed the bomb following the guide posted here. First of all, I do not appear to have any copper or aluminium sealing washers on the banjo connection from the pump? 7zap lists this as a sealing o ring? That doesn't seem right? Surely it should be a crush washer? But, it wasn't leaking.
    Second thing that confused me was that when I removed the brake line, I got a stream of green hydraulic fluid, not brake fluid. Shouldn't this line be clear brake fluid? Has something gone wrong with my brake booster? That would be typical as I just sold my spare
    Nothelle S2 Avant in restoration
    Wr Ur Quattro (also in restoration)

  • #2
    Just read up on this in my Haynes manual and the pipe from the bomb to the servo unit (brake booster) is hydraulic oil. This means the guide posted here is inaccurate. There is no need to cover the brake fluid reservoir to reduce fluid loss as stated. Haynes manual also states sealing washers, not o rings so 7zap must be wrong.

    Nothelle S2 Avant in restoration
    Wr Ur Quattro (also in restoration)

    Comment


    • #3
      The bomb uses hydraulic fluid. Brake fluid is only in your brake lines to the calipers and clutch hydraulics. Later cars like yours will have red o-rings on the bomb to pump line at both ends
      Mike

      http://www.s2-audi.co.uk

      Comment


      • #4
        I had the same issue with my PAS fluid overflowing .. the bomb was about 3 years old.. it eventually stopped. I will get round to swapping the booster again.... At some point

        Comment


        • #5
          Originally posted by Mikes2 View Post
          The bomb uses hydraulic fluid. Brake fluid is only in your brake lines to the calipers and clutch hydraulics. Later cars like yours will have red o-rings on the bomb to pump line at both ends
          I didn't have anything at the bomb end. Can these be replaced with copper or aluminium crush washers? I can't see any groove that would accept an o ring.
          Nothelle S2 Avant in restoration
          Wr Ur Quattro (also in restoration)

          Comment


          • #6
            Originally posted by Monkeymagic View Post
            I had the same issue with my PAS fluid overflowing .. the bomb was about 3 years old.. it eventually stopped. I will get round to swapping the booster again.... At some point
            Oh no! So will I need to replace my booster as well
            Nothelle S2 Avant in restoration
            Wr Ur Quattro (also in restoration)

            Comment


            • #7
              Mine are with alu washers and are fine.

              7zap indicates what seems like O-rings but no grooves on mine and had washers from factory

              Comment


              • #8
                I understood it to be the nitrogen ( I think it's nitrogen) leaking out and pressurises the system . Mine no longer does it as there's no charge left....

                Comment


                • #9
                  I seem to remember some one on here had a bomb with a shrader valve fitted into the bottom so you could pressurise it yourself. Someone else will put me right

                  Comment


                  • #10
                    I found a Citroen specialist who can 're charge them. I've sent it off. I will keep you posted
                    Nothelle S2 Avant in restoration
                    Wr Ur Quattro (also in restoration)

                    Comment


                    • #11
                      Good man.. they look very similar to the grenade looking units used on the Citroen's eg XM BX etc.
                      I wonder what causes them to leak into the hydraulic fluid though? I really should get mine sorted.

                      Comment


                      • #12
                        Citroen air suspension that is...

                        Comment


                        • #13
                          To refill the bomb, new valve has to installed. Then you can put new nitrogen. I know one company in Germany which offers refilling.

                          Comment


                          • #14
                            Re: Crush washers vs O-rings, either could be correct as originally it was somewhat chassis VIN-dependent, but is actually bomb-type dependent, see how to ID type and excellent replacement guide / 15 steps / tips here (listed middle of page):

                            http://20v.org/brakprob.htm

                            Re: Bomb charge pressure described here in factory service trg manual (see 7th screen capture):

                            https://www.s2forum.com/forum/member...es#post2102356

                            Comment


                            • #15
                              Originally posted by Lago Blue View Post
                              Re: Crush washers vs O-rings, either could be correct as originally it was somewhat chassis VIN-dependent, but is actually bomb-type dependent, see how to ID type and excellent replacement guide / 15 steps / tips here (listed middle of page):

                              http://20v.org/brakprob.htm

                              Re: Bomb charge pressure described here in factory service trg manual (see 7th screen capture):

                              https://www.s2forum.com/forum/member...es#post2102356
                              Fantastic
                              Nothelle S2 Avant in restoration
                              Wr Ur Quattro (also in restoration)

                              Comment

                              Working...
                              X