Your brakes should be self adjusting without the need to back up. Take a look at this kit: http://www.autozone.com/autozone/pa...8kolj?itemIdentifier=210302_0_11000_4231 The two silver pieces go together and the gear on the larger piece is turned by the gold colored lever when it is permitted to move enough as brakes are applied. Maybe you have some worn parts. these kits are $14 (U.S.) per side to replace.