OP how does the pedal feel? It should be rock hard almost. If not you have air in the system. Otherwise I'd look into bleeding the brakes
For those claiming you "must" have a disc brake master, I have 4 wheel disc. My pedal, always one stroke, goes down just less than half way and is ROCK hard. My car has 73/4 Duster/ Demon front brakes and a Ford/ Lincoln Versailles factory disk brake, 9" rear axle
