# Hissing sound in the cabin - brake related

**URL:** <https://forums.speedlife.net/t/hissing-sound-in-the-cabin-brake-related/102910>\
**Category:** SON240sx Automotive\
**Created:** [January 9, 2007, 2:29pm UTC](https://forums.speedlife.net/t/hissing-sound-in-the-cabin-brake-related/102910 "2007-01-09T14:29:15Z")\
**Posts on this page:** 1\
**Showing post:** 13

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**Author:** ![FUNGC](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/fungc/32/5539_2.png) [@FUNGC](https://forums.speedlife.net/u/FUNGC)\
**Post date:** [January 10, 2007, 6:04pm UTC](https://forums.speedlife.net/t/hissing-sound-in-the-cabin-brake-related/102910/13 "2007-01-10T18:04:28Z")

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> [@2000 Yukon XL Mods](https://forums.speedlife.net/t/2000-yukon-xl-mods/10877/10):
>
> now before i buy a MC and/or booster, i did mroe reading on old posts and it seems when the booster fails, everyone that has had that problem has a sinking pedle. Mine is just really hard and has very very minimal travel.
> 
> Any ideas? maybe the booster and MC are good, but the lines just need to be bled?

i think you should try this.

also downloading a FSM will help you out alot! just a suggestion 😉

heres also a diagram of what you need to take out in the cabin.

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