Hi all.  I just joined here because I may have a serious problem with my wife's 2000 TT.  Her's is the 4cyl.  I took it out for a quick drive to the store today and on my way back, the brake pedal would not go down and the car lost most of its stopping power.  I was able to pull over to the side of the road safely and killed the engine.  Started the engine, and then the car sounds like it's either idling incorrectly, or is no longer firing on 4 cylinders.  I was able to drive the car back to my residence at a slow speed in lower gears.  Does anyone have any idea on what might have happened?  I plan to take it to a mechanic, but I'm trying to assess what the damages may be.  Also, when I exited the car, I noticed a slight burning smell.  Any feedback is appreciated. 

Take a look to see if some how the brake booster vacuum hose came loose under the hood. Depending on what model it is the 225 or 180 is where it will be located at... I know on the 180 its on the right side look for a hose that runs over the shift linkage and between the engine and air intake it should connect near the windsheild around the brake fluid resevoir. Just a guess dunno.

Take a look to see if some how the brake booster vacuum hose came loose under the hood. Depending on what model it is the 225 or 180 is where it will be located at... I know on the 180 its on the right side look for a hose that runs over the shift linkage and between the engine and air intake it should connect near the windsheild around the brake fluid resevoir. Just a guess dunno.

I have the 180 hp model.  I will go check that out.  From what I'm hearing all signs point to some sort of vacuum leak.

I replaced all my vaccuum and breether tubes earlier this year, cost like $500 and was a major PITA.  But the idle sure sounds a lot better.

Previously Dustin holman wrote:

Take a look to see if some how the brake booster vacuum hose came loose under the hood. Depending on what model it is the 225 or 180 is where it will be located at... I know on the 180 its on the right side look for a hose that runs over the shift linkage and between the engine and air intake it should connect near the windsheild around the brake fluid resevoir. Just a guess dunno.

Nice call Dustin, i had the exact symptoms of the person at the top of this line and wanted to let you know that your post was dead on and extremely helpful!!!  To be completely honest i have to admit i just bought the car today and was having a blast when the brakes seemed to just go hard as a rock and lose total power ..... as i slowed down the idle became eratic and i freaked!  Came home read a ton of total crap before i happened apon this.  Went outside with wife and flashlight and she found the hose right off the bat we put a hose clamp on (just to make sure it was indeed the problem) and went right back out on the road to have more fun.  I've only had this car a day had a BLAST ...... then had to fix it ...... and back to having a blast.  Seems i'm going to have to get used to the repairs but as long as it has the good times where i'm having total fun with it i don't think i'll mind so much.