Whenever I am sitting still at idle with the brake pushed in, the rpms stay still but as soon as I let off the brakes, the rpm raises a little. Say if Iwas idleing at 700, when I took my foot off the brake it would raise to 900. Is this normal or so I have a vaccum problem? Any info would help out.

 

It's called Power Brakes..... Every car newer than like 1965 has them.