Brake bomb washers

[Mike Del Tergo]

I replaced the bomb in my 91 avant last month.  A small PITA but no biggie 
and good to go till this AM as I noticed a snail trail from the car as I 
exit Dunkin Donuts, great.  Took me a minute to place it as Pentosin.  Its 
not very green on the pavement.  Appears to be leaking from the Banjo 
fitting.  I didn't replace the O rings so go to local FLAPS.  They don't 
have the "same" red ones so went with 11mm standard black.  Leak is much 
worse!  ARe there speacial O rings or Audi only?
thanks
Mike