Air leak/Hissing

[Stephanep]

Hi everyone.😀 My Toyota Avensis has developed a hissing noise when the break pedal moves back up. I think it's a servo issue but they are incredibly expensive from the dealership. Any ideas where I can source a second hand reliable part from? Also I read that I may be able to use a spray of some sort to help seal the problem for now? How can I find out where the hissing is coming from to apply this as it seems to be coming from the brake pedal? The hissing noise is coming from the rubber attachment at the bottom of the break pedal (pls see pic)Any pointers greatly appreciated 👍 Thanks.

Edited September 3 by Stephanep

[CrazyMango73]

Does it happen all the time or just at the beginning of a journey? My 2003 hisses at the start only

[MrAurisT]

I had this some years ago; cable tie tight the far/bulkhead end of 'rubber boot/breather' that is on the brake rod (which the pedal is attached to, which then attaches to the servo) in the footwell, hissing stops. All it is (in my opinion) is, over time, the boot starts to 'stick' on the rod not then keeping a vacuum seal. Worked for me.