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Re: BRAKE BOOSTER

To: MS6453@aol.com
Subject: Re: BRAKE BOOSTER
From: tr6taylor@webtv.net (Sally or Dick Taylor)
Date: Fri, 31 Mar 2000 17:29:49 -0800 (PST)
Mitch----A few days ago you drove "100 miles" after getting your engine
back in. Your brakes must've been OK at that time, as you didn't mention
it. So, the poor front braking happened not as the result of all the
disassembly, but sometime after?  I'm thinking the check valve in the
booster has been upset from positive pressure. Try pulling the hose off
at the booster, after starting the engine. Put your thumb, or a vacuum
gauge over the open end of the hose to see if vacuum is present. It
should read the same as at the manifold, or 14 inches as in your case
with an after-market cam. (About 20 inches with a stock cam.)

Usually if the front seal doesn't do it's job in the Master cyl, it'll
leak enough fluid to "show up," and the reservoir level will go down. If
one side of the proportioning valve doesn't see fluid/pressure, it will
be kicked off-center and your brake-dash light will come on.

One thing that is almost certain, pumping the brakes shouldn't cause the
vacuum reading to rise. Does it also change idle rpm? Is the new (?) Tee
clear at the manifold? Since I've never had to do any work on my own
brake vacuum booster. or servo as it's sometimes called, I can't give
any tips as to what may be going on here, should this unit be faulty.
Stay in touch...

Dick


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