I have a 2004 CTT and the brake boost fault light came on six months ago. There was no difference in brake performance or pedal feel, so I kept driving it. A few months in, I took it to the dealer and they told me that the brake booster needed to be replaced and when I challenged them on whether it could be a faulty sensor and not a bad brake booster, they gave me a BS response.

I then went to a good mechanic I trust, who works on a lot of Porsches and he said he checked the brake boost and it was fine. He couldn't find anything wrong with it. I am still driving the vehicle with the faulty boost light on with zero issues.

Has anyone had a similar experience, or have any advice on checking the sensors?

 

well i wouldn't risk it since brakes are the most important thing on your car

 

I got that message when I got a crack in one of the vacuum lines. Does the electric vacuum pump on the passenger side front fender kick on every time you hit the brake pedal? My pedal was fine as well with the error code because the crack wasn't big enough to overcome the vacuum pump assisting the engine vacuum. One of the tell-tale signs I had was that the brake pedal was hard shortly after killing the engine. With everything fixed I can jump in and the pedal is still soft due the vacuum still being captured in the system after the engine has been off for some time.

 

I second that- I got the warning also and had a crack in the vacuum line. It was the line on the passenger side behind the windshield washer resivior. The line at fault came off the vacuum pump. Check for leaks.

 

Same here. I got the light warning ... and they replaced the entire booster (under CPO). I did hear the booster cycle up every time I stepped on the brake. Get it fixed! Most likely a leak or some sort.

 

Got the same error code, vacuum plastic line is like 135. I did a fix for like 6 bucks.

 

Ya what size of tubing did you use ?