The backplate is a heavy stamped steel disc bolted to the axle housing or suspension knuckle. It serves as the structural foundation for a drum brake, providing mounting points for the wheel cylinder, brake shoes, return springs, and adjuster hardware. It also acts as a dust shield, keeping road debris and water out of the friction surfaces.
Heard on the job
The shoe hold-down pins pulled right through the rusted backplate, so the whole brake assembly fell apart.
Also heard as
- backing plate
- brake backing plate