need help finding out what happened to my brakes it all started early in the year i felt my brakes were loosing power/vacuum i believe it was the original power disk brake set up well i was drag racing and something must have got in between the rotor and brake and cracked my driver side rotor so i brought it to my engine builder and had them replace brake pads, rotors, power brake reservoir and install a vacuum pump already had a vacuum canister. brakes worked good better than before until going 108 at the end of the quarter mile my master cylinder went out and i barley got the car stopped with the rear drums. i also needed the car fixed in just 4 days to make it to the bracket finals so i had a racer that is also a mechanic replace the master cylinder brakes worked better than ever. until today when i just got it back from getting new exhaust on it and went to unload it of the trailer and had no brakes making the car roll of the trailer too fast braking my front splitter. so i am asking what could be wrong because everything is basically new and where in PA could i get it fixed. thanks