Sun fire stall when brake is pressed

[Swafford]

Hi I have a 98 Pontiac sun fire and it runs and drives up until the brake is pressed. I performed some experiments and it can be in any gear (drive park neutral reverse) as soon as the brake is applied the engine stalls out

 

[melsg5]

check for a leak in the vacuum line running to the booster or the check valve is bad or the booster itself is bad