Brakes did not work when I bought it 2nd hand. Found the rectangular slot (keyway) in the drive shaft was missing the 3/16 key that connected the drive shaft to the brake. ACE Hardware sells 3/16 keys for $0.80. It is 1.25" long and needs to be cut down to 3/4" to slide in place. You'll need to unscrew the 3 screws holding the disc brake to the ring that is around the drive shaft to access this slot.
about 2 years ago
A 3/16" key is a little too small for the Razor Dune Buggy brake rotor and axle. Since a 3/16" key is smaller than the original key it could work its way out of the keyway and damage the rotor or axle in the process.