I'm in the long laborious job of bleeding brakes after replacing all flexi pipes. Old age and cold weather made me think what's the cost for someone else to do it? Local Audi wanted £60 for diagnostic (my VCDS showed no faults) then whatever to fix???? Rang Quattro Tech and had a very pleasant, helpful conversation. Being told that this job is the proverbial PITA and they would willingly take my money, BUT, as you've started just keep going, about 3 - 4 attempts should get it sorted. Very pleased with their service and to find out that the Revo Stage 1 done by themselves prior to my purchase, can be modified to suit my driving preferences, was something I didn't know. Maybe something for Santa's list!