91 gmc sierra step on brakes and idle goes up and i hear an air leak behind the pedal

1991 GMC SIERRA
15,000 MILES
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LEXYTRIZ
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  • 1 POST
i have already replaced brake system rear and front brakes. checked braked system its fine. ive bled em and there is no leaks.
Apr 17, 2012 at 5:49 PM
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FIXITMR
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  • 9,990 POSTS
check brake booster for vacuum leak
Apr 17, 2012 at 5:57 PM
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FIXITMR
  • CERTIFIED EXPERT
  • 9,990 POSTS
check VAC line check valve to booster too.
Apr 17, 2012 at 6:10 PM
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