ok i was looking at my buddys 82 half ton four by pick up. its a little basterdised, not sure if it will afect anything, new moter ect. was looking at his vac lines explaning how stuff worked to him and snaped the little plactice resistance thinggy in the brake booster vac line. so i caqpped it for him so he could go get a new one. he said his brakes suck and NOW THERE BETER?!?!?!?!?! so i dont get it, his cyinder looks fine and there is no evadence of main seal leaking. could his diaframe be killed? is there a way to check that?