Hissing noise

[Mactat2]

Hi Guys, just bought a 2007 A3 1.9TDI 140k on the clock and full service history. When you start it you get a hissing from the drivers foot well. Guessing a vacuum leak? it hiss's until you press the brake then it stops, release the brake and it starts again. Brakes work fine, anyone know what could i should be checking?

Thanks

Edited October 15, 2022 by Mactat2

[Steve Q]

Could it be the brake servo?.

[Mactat2]

its certainly in the right area. Ill have a look tomorrow evening. Was just wondering if theres anything common that usually causes it?

Thanks Steve

 

[Steve Q]

On 10/16/2022 at 7:35 PM, Mactat2 said:

its certainly in the right area. Ill have a look tomorrow evening. Was just wondering if theres anything common that usually causes it?

Thanks Steve

 

No probs at all. Did you get to the bottom of it?