Uhhhh, not entirely spot on Carl want to be technically correct here.
The advantage to the Bendix brake or the Duo-Serve as GM called it,
over the Huck brake was that it was a single anchor type with
a single adjustment for both shoes. But more importantly this
design was self-actuating or self-energizing, meaning the
shoes were pulled into the drum by the momentum of the vehicle
when applying the brake both forward or backward. This eased
the pedal pressure over the Huck style brake.
Only the later versions of the Bendix style brake were they
self-adjusting, somewhere in the late 50's or early 60's if
I remember correctly. My memory is fuzzy as to the exact year
GM introduced them, Dave or Jerry can probably zero in on the
exact year.
dg
