Originally posted by DennyW
Sounds like the diaphram is good. The other question about all the way to one side. A lot of these are adjustable. You can check by where the vac hose hooks up. They may or may not have an adjustable allen inside. Second, it wouldn't be all the way because it is spring loaded for returning back to the base position. That's why a vacuum pump was mentioned to move it all the way as far as it will go.
denny is right tcodi, if it held at all its ok. if the diaphram was busted then it wouldnt hold any pull.