Bad Check Valve???

I did not take the booster apart yet but found some major problems. The front brakes were totally shot. Pads were metal to metal. Hoses were ready to explode. Probably real bad on the inside and holding pressure keeping the pedal down. Rear brakes were way out of adjustment. So I put on new hoses & pads and adjusted the rears real nice. Pedal feels great now but raining out so test drive will be tomorrow. Also got the New Cooper Cobra 2257014's on. Pictures to follow.
Thanks for all the help.

P.S. I was told how the Previous owner was such a great mechanic which is why I didn't check all this stuff first. Apparently he just neglected all maintenance items on this car. There's also some looseness in the front end but not real bad. I will check and repair the Front End this week.