# rpms drop while holding the brake

**URL:** https://forums.speedlife.net/t/rpms-drop-while-holding-the-brake/102200
**Category:** SON240sx Automotive
**Created:** [December 3, 2006, 10:07pm UTC](https://forums.speedlife.net/t/rpms-drop-while-holding-the-brake/102200 "2006-12-03T22:07:45Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![shift\_fun](https://avatars.discourse-cdn.com/v4/letter/s/d07c76/32.png) [@shift\_fun](https://forums.speedlife.net/u/shift_fun)
#### Post date: [December 3, 2006, 10:07pm UTC](https://forums.speedlife.net/t/rpms-drop-while-holding-the-brake/102200/1 "2006-12-03T22:07:45Z")

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at the title states , recently ive been noticing then when im stopped at the light and hit my brakes my rpm dips down from 750 to about 500 and then after a few seconds back upto normal.

what could be the cause for this flucktuation?

i have a 91 5speed SE if that helps.

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### Author: ![Gonad](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/gonad/32/5481_2.png) [@Gonad](https://forums.speedlife.net/u/Gonad)
#### Post date: [December 3, 2006, 10:25pm UTC](https://forums.speedlife.net/t/rpms-drop-while-holding-the-brake/102200/2 "2006-12-03T22:25:04Z")

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Vacuum leak.

Check all vacuum hose connections.

Download the FSM if you have to.