Brake shoe

Brake shoes are components to which the brake lining is fitted. We also sell brake shoes already fitted with new brake lining. We recondition brake shoes to produce lined brake shoes in our own workshops. They generally consist of a steel or cast-iron shoe body with riveted brake lining. When the service brake is applied, the brake camshaft presses the brake shoes radially against the running surface of the brake drum. The resulting friction converts the force from the pneumatic brake cylinder into braking torque. Drum brakes are commonly found on heavily loaded axles, in off-road and distribution applications, including MAN F90, F2000, L2000, TGM and TGS, and Mercedes SK, Atego, Axor, Arocs and Vario. Drum brakes also remain relevant on specific axles or versions of buses such as the MAN Lion’s City, Mercedes Citaro and Neoplan coaches.

A brake shoe set must match the axle and brake configuration exactly. Key factors include drum diameter, nominal brake width, position as leading or trailing shoe, lining fastening method, pivot point design and the geometry of the contact area for the S-camshaft or wheel brake cylinder. The friction lining also differs in thickness, length, coefficient of friction and thermal load capacity. Softer linings often provide immediate engagement on lighter vehicles, while harder composite linings are more resistant to high drum temperatures, heavy axle loads and prolonged descents.

Also pay attention to the combination with brake drums, return springs, brake camshafts, brake adjusters and brake cylinders. Incorrect lining hardness or a differing shoe radius causes uneven contact with the drum, local overheating and reduced braking force. Parts must always be identified using the vehicle chassis number. Visual comparison or selection based solely on the model name is never sufficient, as the same vehicle series may have multiple axle, drum and brake variants.

Typical faults include insufficient lining thickness, unevenly worn brake lining, glazing, loose rivets, heat cracks and contamination from grease, hydraulic oil or leakage from a wheel bearing seal. Metal-to-metal contact between the rivet heads and the brake drum irreparably damages the running surface. Blue discolouration, hairline cracks or a sharp burning smell indicate thermal overload, for example due to a seized brake camshaft, incorrectly adjusted brake adjuster or insufficient brake cylinder return.

Only remove the drum and brake shoes after the vehicle has been safely supported and the spring brake cylinders have been secured according to the factory procedure. Measure the lining thickness at several points using a vernier calliper and compare it with the specified wear limit. Then check the internal diameter of the brake drum using a drum gauge or internal micrometer; exceeding the maximum rebore diameter requires replacement of the drum. Use a dial gauge to check radial runout and inspect the running surface for grooves, heat spots and cracks. Also assess brake camshaft bush clearance, the condition of the roller bearings in the hub and the free operation of the automatic brake adjuster.

Always replace brake shoes per axle and fit new return springs if they show corrosion, stretching or fatigue. Clean the backing plate surface and the brake shoe contact points, but apply only the specified heat-resistant lubricant to sliding and pivot points; the friction lining and drum running surface must remain completely free of grease. After installation, check the basic adjustment, brake cylinder stroke and brake force balance on a brake test bench. A correctly selected brake shoe set, combined with an inspection of the drums and brake actuation system, prevents downtime, uneven brake readings and costly consequential damage to hubs and axles.