I recently had my alternator go out on me and I left the battery disconnected for a couple of days till I could put the new alternator in. So after the new alternator was put in my car has a bit of trouble idling. Does anyone know what could be wrong on top of that for some reason my brake pedal is really hard to press and my car doesn't stop very easily. I find myself really stomping on the brake pedal in order to get it to stop

 

It sounds when you put the new alternator in, you either unplugged a connector or a few hoses....your master brake cylinder isn't working properly and your idle is off....who put the alternator in?