Chevrolet Astro Brake Pull

I Have A 2001 Chevy Cavalier, With Abs. Starting Winter My Rear Right Tire Started Locking Up And Causing My Car To Bend Down To The Right....

When Coming To A Fairly Hard Stop The Van Wants To Pull To Left. Also When Driving Slow (30 And Below) The Van Wants To Fade Left. I Guess...

I Have A 94 Astro Van And My Girl Drove It Ten Miles And Belt Broke She Says Every Ten Miles It Breaks Do I Need To Replace The Pully Or Is...