Question about 1984 Ford F 150

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19984 F150 Hissing Brakes

I have a 1984 F150 that makes a hissing noise when I put on the brakes, which still work very well. There is no hissing when my foot is off the brake. The hissing is louder inside the cab than outside, it sounds like a vacuum leak. Under the hood, the big drum bolted to the firewall looks pretty rough, the paint is peeling off the lower half & there's a lot of surface rust. The brake pedal pushes a shaft into it, it's obviously a critical bit. Is that some sort of accumulator?

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You need a new power booster mine did the same thing

Posted on Dec 10, 2011

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This noise is the seal for the power brake booster leaking, you will have to replace the vacuum booster to fix it.

Posted on Nov 12, 2008


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