need more stopping power. vacuum issue?

[blackbeaSSt]

for the first time this morning i was scared ****less when stopping. person in front of me slammed on their brakes and i was a decent ways away but going pretty fast. i started to hit the brake and realized she was stopping faster then me! i came within a foot of hitting her and i was standing on my brakes.

the guy i bought the truck from said that the cam is pretty much taking up all the vacuum and thus the brakes aren't all there.

any ideas on what i can do to test or fix the problem before its too late