So my car has had problems with the brakes since I bought it..Bleeding the air numerous times has not helped, replacing all four calipers/rotors has not either..

So we were looking around the engine bay, and my buddy pulled out that big hose going into the brake booster, and it didn't make that "whoosh" sound we are used to hearing from the brake boosters. That should be under vacuum but obviously it wasn't.What does this tell us? Faulty brake booster?

 

If you pull the check valve out of the booster it should have vacuum for a little bit after the motor has ran. It will bleed off at different rates, but hours later not likely to have a lot of vacuum there.
After shutting it down, pump the pedal how many power assisted pedal depressions do you get?

 

Replace the check valve. Pressure should never really bleed off. I doubt the booster is bad nor the check valve being your problem.

 

We pulled the booster hose off no more than 10 minutes after the engine was off. So it maybe the check valve?