Brake Shoe

The brake shoe is a key part of drum brake systems, used in passenger cars, trucks, and trailers. It is mounted inside the brake drum and, when actuated, expands outward to press the friction lining against the drum's inner surface, converting kinetic energy into heat. Brake shoes are specified by vehicle model, drum diameter, lining material, and friction coefficient. Grades differ in lining composition (e.g., organic, semi-metallic, ceramic) and performance characteristics such as heat fade resistance and wear rate. The shoe body is typically made of steel (e.g., SPCC, SPHC), and the lining is attached using adhesive or rivets. Key parameters include friction coefficient (0.35–0.45 at 100°C per GB 5763-2008), drum diameter (200–420 mm), lining thickness (4–12 mm), lining width (40–120 mm), shoe arc length (100–300 mm), shoe web thickness (3–6 mm), shoe radius tolerance (±0.5 mm), surface roughness (Ra 1.6–3.2 μm), shear strength of lining (≥1.5 MPa per GB 5763-2008), maximum operating temperature (250–400°C), wear rate (0.1–0.5 cm³/MJ per GB 5763-2008), and weight (1.5–8 kg per shoe). Relevant standards include GB 5763-2008, ISO 6310, SAE J661, and QC/T 239. These standards serve as procurement and verification references; they do not imply certification of any specific product. Always verify model-specific values and standards with the legal manufacturer or supplier before use.

When the brake pedal is pressed, hydraulic or pneumatic pressure forces the wheel cylinder pistons outward, pushing the brake shoes against the rotating drum. The friction between the lining and drum converts the vehicle's kinetic energy into thermal energy, slowing the wheel. The shoe's curvature matches the drum's inner radius to ensure maximum contact area and even wear. The lining material and shoe geometry are selected based on vehicle application and operating conditions. Proper adjustment and maintenance are essential to maintain braking performance and prevent premature wear or failure.