[DeTomaso] Vacuum to the Brake Booster

[Michael Becker]

Hi Gang,
What sort of vacuum level should I expect to read on the hose that feeds the
Brake Master resevior?  I am having some serious brake fade at low rpm's.  I
have to rev the engine to get the brakes to respond.  They will work while
driving, but while coasting, the power brakes seem to just fade away.  If I
tap the throttle, I get them back.  It's very unconfortable.  I was thinking
perhaps I have a vacuum leak in the trans-atlantic pipeline that runs from
the intake manifold to the booster.  Am I barking up the wrong tree?  Could
this just be a bad booster/resevior?  I have a high lift cam and have always
noticed that when the car is idling really slow, it feels like there is no
power assist. 
Mike