PONTIAC GRAND PRIX BRAKE

When You Press On The Gas It Feels Like The Parking Brake Is On. And When You Pick Up Some Speed And Let Off The Gas It Slams To A Stop....

I Need To Remove The Caliper Bracket. It Has 2 Torx Bolts. What Size Do I Need To Get. Thanks

I Noticed When I Took The Caliper Bolts Out That 1 Bolt Had A Rubber Tip/cover On It And The Other Didn't, Is There A Reason For This...