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My booster has been leaking for a long, long time. So, I have a new one to install with a dual m/c for my '66--I can't wait.

However, I noticed on the old booster where the vacuum line(s) connect, there is no seal. It moves around quite effortlessly and looks as though it could be snapped out of the brake booster body quite easily.

This isn't right, is it? On my new booster (which I'm not ready to install), the seal is TIGHT and it barely moves. Could this sloppy union between the vacuum check valve and booster body be the source of the leak I hear under the dash when I apply the brakes, or would that be the diaghram in the booster?

Currently, my car wants to idle at 1200 rpm, so I must have a vacuum leak somewhere.

Thanks for your expertise--you guys always figure this stuff out!

Doug
 

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Yes to all your questions.

That is a vacuum check valve that is supposed to hold vacuum in the booster. It is installed in a rubber grommet which has to have a good seal to the booster housing to insure it will work right. If it doensn't seal you will have a major vacumm leak which will affect your engine as well as your power brakes.

As a simple test, if you put a hose on the end of that fitting and blow into it, you shouldn't be able to, because the vacuum check should close. If you suck on it, it should allow you to for an instant, but it should be sealed so tight that soon you wouldn't be able to pull any more air out.

You should fix it and sell it on . I got around $100 for my old one IIRC. You can disassemble the casing on with a bench vise and a big wrench to check the diaphram. Just be aware that there's a big ass spring in there, and if you're not carefull, you'll launch the top of the housing about 10 feet when it comes loose.

Phil
 
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Discussion Starter #3
Thanks Hoosierbuddy. As a fellow Hoosier (born and raised but now in Michigan), I am indebted.

And I'll watch out for that "big ass spring." Is that the technical term ascribed by Ford?

Doug
 

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Actually, they call it "(1) Spring, big-ass." IIRC.

Good Luck....by the way...my earlier post mentioned something that rhymes with "eee hay" but it got stripped out of the post by the InfoPop software. Think of "somewhere people sell stuff where buyers often pay entirely too much money."

Phil
 
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