See Figures 1 and 2
Brake shoes may contain asbestos, which has been determined to be a cancer causing agent. Never clean the brake surfaces with compressed air! Avoid inhaling any dust from any brake surface! When cleaning brake surfaces, use a commercially available brake cleaning fluid.
Fig. Fig. 1: Exploded view of the rear drum brake system components (drum removed)
Fig. Fig. 2: Some special tools are required when servicing brake drums