Brake booster vacume pump.

The street driving is great even at stop signs no problem, where the trouble comes is if I turn around in the driveway which is slightly up hill im using them alot at a idle and sometimes get the hard pedal like no power brakes left. I can live with it over the 300 dollar fix, Im more concerned if son or wife would pull it out of garage and say oh ****. If they only tap the pedal once or twice its ok but anymore than that it get hairy.