You need to get your rear brakes bled. Soak the bleeders with pb blaster for a couple dats in a row then see if you can crack them. Start rear right, then rear left, then front right, then front left. Then adjust your rear brakes. Jack the rear up, turn the adjuster in and spin the tire until you hear the brakes touch and the tire starts to drag, then back it out a turn. Do it on both sides and you should be good to go.