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leaking brake fluid

Discussion in 'A4/S4 forum(B5 Chassis)' started by fARQUARE, Jul 6, 2009.

  1. fARQUARE

    fARQUARE Member

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    Car: 1997 a4 1.8t sport avant

    After having a full load in the car at the weekend I thought the brakes were particularly bad (worse than usual). When i got home i checked the resivoir as I got the brake light warning on the DIS, to find the fluid was at a level just below min. I topped it up and pumped the pedal a few times and it pretty much just dropped to the floor with constant pressure.

    I'm leaking fluid from the N/S/R caliper, i took the wheel off and had a quick look but I couldnt really see where it was coming from (the dripping stopped by the time i moved from the car to the rear wheel). The flexi-hose its self didnt look perished and the banjo bolt at the union was tight but it seemed to be coming out somewhere near this joint.

    Is this a common problem on the rear?
    Is this likely to be the caliper or the hose?

    Cheers
     
  2. aragorn

    aragorn "Stick a V8 in it!"
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    if its leaking enough that the pedal goes to the floor even after pumping it, its going to be obvious from looking at the caliper where its coming from. I'd get someone to look while you press the brake pedal, it will likely become obvious!
     
  3. fARQUARE

    fARQUARE Member

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    trouble is, its difficult when you dont have someone there to give a hand.

    Cars booked in to be looked at this week anyway, i dont have the time or the equip to bleed the brakes after taking off the caliper/flexihose.

    I'll post back to let you know what was at fault. As a sidenote, i had the O/S/F flexi hose replaced a few weeks ago because it was bulging near the union (it wasn't leaking though). This one would be on the same circuit?? Coincidence?

    Cheers.
     
  4. Broken Byzan

    Broken Byzan Photographic Moderator
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    I would be interested to hear what they come up with. It sounds like its either the flexi or the Banjo connection. But it will need bleeding. I hope they change all of the fluid as it will make a marked difference in the brake feel
     
  5. fARQUARE

    fARQUARE Member

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    right, update time.

    Car went in to the garage who diagnosed a leaking flexi hose and fited a new one.
    After topping up the fluid and trying to bleed the brakes they noticed the resivoir for the fluid was cracked, so was leaking from there too.

    The only thing i can think is that the excess force on the pedal and through the servo combined with the leak from the back has forced the bottle to crack under extreme vacume??

    Otherwise im not sure how the bottle would crack.
    Anyway, all seems good now.

    Cheers
     
  6. aragorn

    aragorn "Stick a V8 in it!"
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    The bottle would have cracked when they hooked up their pressure bleeder.

    They arent that strong and a few PSI too much will crack the bottle.

    I blew mine up the first time i tried it, and had to replace it with one from a scrapyard Audi 80, every A4 bottle in the scrappy was gone. 80 one is slightly smaller, but works just fine.

    Bled it up fine with the replacement bottle with exactly 10psi in the bleeding kit though.
     
  7. Broken Byzan

    Broken Byzan Photographic Moderator
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    Yep as Kev said, i coverd my engine bay and bonnet in fluid when i connect the easibleed at 15 psi.

    A new resevoir and bled by hand saw good brakes. My bottle was around a tenner iirc from VAG parts when they were around. I carefully removed excess fluid and removed the bottle and popped the new one on and refilled without the need to bleed the whole sysytem
     
  8. aragorn

    aragorn "Stick a V8 in it!"
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    Yer i changed mine without getting air into the MC too, just carefully removed it.

    Quite a good way to do a fluid change actually!
     

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