Where is the vacuum line that keeps my car crank and where is it located?

you may have a vacuum leak in the power brake booster. 19 inches of vacuum required to operate. turn car off, pump brakes and then crank. If the pedal goes down, listen for a hissing sound to indicate failure. if not you will need to check all hoses for a leak(hissing)

Agreed bad booster or bad master cylinder. Check for vacuum leak but also check to see if brake fluid is being lost. i have seen it where the master vylinder fails and every time the brake is depressed it would dump fluid right into the booster and foul out the plugs. Alternate check is to pull the big vacuum line going to booster and plug it with a bolt and some tape. Do not drive the vehicle like this just driveway test to see if it still stalls when you hit the brakes. If it does stall then the vacuum leak is else where. If it doesnt then its booster or master cylinder.