Amoi china boking subang usjWorking for fedex express redditA drum brake system contains brake drums, shoes, backing plates, and wheel cylinders. Brake drums made from cast iron, bolt onto the wheel hubs or axles, and spin at the same rate as the wheels. The rest of the components are confined to the inside of the drum. Inside each brake drum sits 1 wheel cylinder and 2 brake shoes bolted to the backing ...