hissing sound

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Nov 1, 2006 | 04:42 PM

sailorjohn

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Joined: Oct 2006

Posts: 199

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From: Blue Springs, MO

hissing sound

I'm getting a Hissing sound from under my dash! It sounds like maybe it is comming from a vacuum line. When ever I press the brake peddle the hissing stops for a short time it also stops or changes pitch when when I accelerate or decelerate. Other problems that I am having in that area are tach not working (some times it jumps around but it is usualy pegged out on top or bottom), speedometer jumps back and forth about 5 mph with no speed change. I am also having problems with my high beem indicator light working intermitently.

These problems are on an '86 B II 2.9 FI w/ 4WD 5 sp manual trans.

John

Nov 1, 2006 | 07:09 PM

Franklin2

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Joined: Jan 2001

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From: Virginia

Disonnect the vacuum line going to the brake booster, and see if the hissing stops(plug the line so you can run the engine). Your brake booster may be bad.