Floor Vacuum Hiss

[rsolis]

So I noticed when I was driving what sounds like a vacuum leak but it's coming from the inside underneath the steering wheel. So I went under and didn't see a crack in the vacuum hose however I did see this fitting possibly cracked (see pic)

It only hisses while in drive and doesn't immediately start I have to drive like .25 miles. The hiss will go away when I accelerate. Any ideas on what this might be? It's hard to figure it out because it only happens whole in drive. If I shift into neutral or park the noise goes away.




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[DerekTheGreat]

Info on what kind of car you are driving would be good. Sounds like a box though. The hiss could be related to the auto e-brake release which IIRC is near the floorboard on the steering column, it's a white crescent shaped doo-hickey.

The hiss would go away as you accelerate because it is tied to engine vacuum. Engines make less manifold vacuum as the throttle is opened.

[SeanP]

Info on what kind of car you are driving would be good. Sounds like a box though. The hiss could be related to the auto e-brake release which IIRC is near the floorboard on the steering column, it's a white crescent shaped doo-hickey.

The hiss would go away as you accelerate because it is tied to engine vacuum. Engines make less manifold vacuum as the throttle is opened.

+1 to this. My old crown vic made the same noise. If it drives you crazy, you can plug the line going to it. But then it wont automatically disengage the parking brake, so you'll need to use the lever near the pedal. I just lived with it.

[rsolis]

Yeah just gonna plug that bitch. Never use the parking brake. I'll let you guys know if that did the trick. Appreciate it


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[GM_Guy]

It will do the trick.

Alex.

[rsolis]

That did the trick. Thanks again all


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[DerekTheGreat]

Sweet.

[rsolis]

I didn't even know the parking brake had an auto release lol.

Everytime I've ever used it it just sticks and I have to drive the hell out of it to get it loose, the very last time I had to take apart the rotor


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[DerekTheGreat]

That dysfunctional crescent thing could've been part of the reason why. I say part of because you're in Michigan and that stuff tends to rust itself seized.

[SeanP]

Awesome, glad it worked. I don't know much, but every so often something comes along that I can participate in!

[BigMikeIT]

Had mine developed a crack about 15 years ago. Replaced it and the auto release worked again.

The parts guy at a Ford dealer once said the cars either have the pull handle or the vacuum release, rarely both. Then again it seemed there was a reason why these guys staffed the parts desk.



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[tjc78]

I don't know when it changed but I know both my 89s had auto release and a traditional pull handle to release.

Pretty sure 90/91 had the push to release even with auto.

Older models (including my 79 barge body) only had a little lever hidden under the dash. Kind of a pita if the auto release fails.