I know there are a few other threads on this, but I want to be very specific, becuase I am trying to decide if I need to drive 2 hours to get this checked.

I am hearing a hissing noise that seems to be coming from the pedal area. I hear this when I let off the brake or the accelator (so basically when I am coasting.) If I depress the brake, it stops, but as I let it off, it starts again. If I depress the gas, it stops... well, you get the picture. The strange part is, if I gently tap the brake the hissing stops, even if when I am coasting (still in drive, my mini's an automatic, but I am not pressing the brake or gas.)

I do not hear this noise when in park or when the engine is off. I don't have the hardness that I have seen mentioned in the other posts on this topic. I pushed my brake 10 times with my car off and it still depressed just fine.

The noise is not excessively loud. It gets louder the faster I am going, and I really only hear it if the ac and radio are off.

I have had a friend who is a mechanic look at it, and he thinks it is a vacuum leak in the booster. I really have no idea.

My MINI has 55k miles on it. I talked to the service center in Indy (2 hours away) and they said if I bring it in, they can see if MINI will still cover it at least partially since the brakes are a vital part of the safety of the car. They told me that they have never had to replace a brake booster on any MINI, though, so I think they are doubting that that is what it is. (I find this doubtful)

So, my first question is, is it possible that this noise is normal? (fingers are crossed)

Second, Is there anything besides a brake booster vacuum leak that would cause this?

If not, should I drive to Indy, have them diagnose it, probably have to drive home then back to drop it off so they can order the part and MINI may cover it partially.. or... should I just purchase the part directly for $350 and have my mechanic replace it?

Also, if it is a vacuum leak, is there any way to fix it without having to replace the whole master cylinder?

One more thing... If it is just a vacuum leak, what harm am I subjecting myself and my car to by just driving it as it is?

 

I spoke with the Mini service manager and he said that the brake light should be lit if there is a vacuum leak... I thought about his, and I actually had to get new brake pads right after I got my MINI (3 months.) I kept hearing a hitting noise. It was actually where the pads were so wore that the edge was hitting or something like that.. My mechanic was shocked that my brake light never came on because they were almost bare. I'm wondering now if my sensors are malfunctioning. My brake light has never came on.

Thanks in advance!