Brake lining

Brake pads convert the operating force of hydraulic or pneumatic braking systems into controlled friction on the brake discs. In heavy-duty transport, they are a wear part with a direct impact on braking distance, thermal load and the service life of brake calipers and brake discs. This category includes brake pad sets for disc brakes on MAN trucks, buses and vans, including TGL, TGM, TGA, TGS, TGX, TG3 and TGE, as well as Mercedes Atego, Axor, Actros, Arocs, Econic, Sprinter, Vito, Citaro, Intouro and Tourismo. Specific versions are also available for MAN Lion’s City and Lion’s Coach buses and Neoplan coaches.

A brake pad set generally consists of two brake pads per brake caliper, with a steel backing plate, an insulating intermediate layer and applied friction material. The compound varies according to axle load, operating profile, permitted operating temperature and the combination with the brake disc used. Heavier applications, such as tractor units with D20, D26 or D38 engines and Mercedes vehicles with OM 470, OM 471 or OM 473 engines, often require brake pads with greater thermal stability and wear resistance. City buses with frequent stop-start cycles, on the other hand, require a compound that engages quickly and predictably even at lower temperatures.

This category exclusively includes brake pads for disc brakes. For disc brake pads, the shape of the backing plate, the position of the guide lugs, the thickness of the friction material, the connection for wear contact sensors and the brake caliper type are among the factors determining the correct choice. Brake disc diameter, nominal disc thickness and the brake caliper version are also decisive. Parts must always be identified using the vehicle chassis number. Visual comparison or selection based solely on the model name is never sufficient, especially for vehicles with different axles, brake options or model years.

A wear warning on the instrument panel, metallic grinding, reduced braking performance or a vehicle pulling to one side when braking requires immediate inspection. Measure the remaining friction lining thickness using a brake pad thickness gauge through the brake caliper inspection window. Compare the inner and outer brake pads, and assess both sides of the same axle. A significant difference in thickness often does not indicate a problem with the brake pads themselves, but rather seized brake caliper guides, a stiff piston, corroded pressure plates or insufficient return movement of the mechanism.

First check whether the brake caliper can move freely over the guide pins and measure the axial clearance in accordance with the brake caliper manufacturer's specifications. Then remove the pads and inspect the backing plates for heat discolouration, unevenly worn friction material, cracks and lining separation. Next, measure the brake disc thickness at several points with a micrometer and check radial runout using a dial indicator. A disc below the minimum thickness, with thermal cracks or excessive runout, must be replaced together with the brake pads. Also check the operation and wiring of the brake pad wear sensors; a damaged sensor may retain a fault message despite new pads.

Always replace brake pads per axle and per brake caliper as a complete set, never just one individual pad. Clean the contact surfaces in the brake caliper without inhaling friction material or dust, inspect the fitting springs, pressure plates and retaining components, and replace damaged parts. Do not use grease or assembly paste on the friction material or the braking surface of the brake disc. A suitable heat-resistant lubricant may only be applied to the specified guide and contact points.

After installation, the brake caliper must be reset according to the correct procedure and the pads must be able to centre themselves. Carry out a functional brake test, check the brake pressure on pneumatic systems or the hydraulic brake fluid level on vans, and read any ABS/EBS fault codes. A carefully selected set of brake pads and rapid availability of suitable brake components limit unplanned downtime and prevent costly damage to brake discs and brake calipers.