I have a 1999 audi a4 quattro that has a few problems which i need some help diagnosing. First when I brake, the braking is choppy not smooth. Also when I brake completely, the RPM's fludder or it feels like the cars is going to stall and sometimes it does stall out and this is an automatic car. The third thing is can you bleed a turbo out because when I first start drving the car it makes a fluddering noise coming from the engine but only when I hit the peddle. Once I have been driving for about a minute or so the noise goes away probally because the oil has heated up. I really need your help and would appreciate it. Thank you.

 

Sounds like a vacuum leak.. look at the hose to the brake power booster. Or maybe the booster itself.