yalls helping thoughts

[bigredchevy]

i have i 86 crew cab c20, vacum brake booster jb7 ect... ive changed every thing now twice over in two mounths first booster faild (pedle gate hard) and did shoes wheel celinders pads for front and lines in back wheight vale stoped working then so bypassed that now two mounths later i drive 30 miles to town ond stop for food now no brakes soft pedle to the floor slowly drive home and get a new booster and master cylinder onder warenty boom still the same thing nothing ive bleed it agin and agin, no air, no leks, no puddles, still no pedle when running im at my wits end, this is two weeks with no truck and thats all i have to drive plz help with idears