Most hand brakes on a bike consist of a line that runs from a lever to a caliper. The cable pulls the caliper closed. This closing action presses nubs or tabs up against the tire to slow or stop the rotation. When brakes need repair, this may require a basic adjustment. The cable becomes loose and fails to pull the caliper tight enough to make it effective. Standard repair of a hand brake, such as tension adjustments or replacing the tabs, should take less than an hour.
Find the end of the cable that attaches to the hand lever or caliper. You may need to adjust the cable in both locations. Turn the cap that sits on the end of the tube near the attachment. Rotate the cap once or twice counterclockwise. This will loosen the cable.
Turn the holding bolt with a wrench to loosen it. Turn the bolt counterclockwise two turns, just until the part wiggles. The location of this bolt will depend on the style of brake.
Grab the wire sticking through the lever or caliper with a pair of pliers. Pull downward on the cable and tighten the holding bolt simultaneously. While you pull the cable tight, the bolt will secure it.
Secure the end cap back in place by pushing it onto the cable tube and turning it clockwise.
Replace worn rubber tabs on the calipers by removing the caliper from the bike. Loosen the holding bolt and disconnect the cable. Pull up on the caliper. For some bikes, this will be enough to dislodge it so you can access the tabs. Pry the old tab off with a screwdriver and insert a new tab in place. The new tab will snap into place with pressure from your fingers. Return the caliper to its place on the bike.