I haven't driven the car for a long time. Is it normal for tge pedal to become firm for a second after pushing the pedal for few times in a row then it goes back to normal in a second. What could be the reason?
Yes, you are using up the brake booster, which is operated off of engine vacuum. Shut the car off and push the brake a few times. You use up the booster and then no power assist. Same thing if you do it several times quickly with the engine running.