TOPRAN brake disc (408 931) is precision-machined from high-grade grey cast iron for uniform heat dissipation and resistance to thermal cracking under heavy braking. Key dimensional data — Rim Hole Number: Rubber -Hole, Fitting Position: Front Axle, Height [mm]: 50 mm, Brake Disc Type: Carbon — ensures the rotor geometry meets OEM tolerances for run-out, thickness, and parallelism right out of the box. Compatible with MERCEDES-BENZ vehicles; the hub-centric bore and bolt-circle pattern match the original specification exactly. Direct replacement for OE references: 083 521 0021/PD, 0 986 479 A60, 09.B807.51, 10 10 7501 and 101 more. TOPRAN rotors are checked for surface hardness and dynamic balance before dispatch, keeping braking distances predictable throughout the service life of the disc. Brake discs generally last 50,000–70,000 miles, though this varies with driving habits, terrain, and pad compound — heavy urban driving or towing shortens disc life considerably. Warning signs of worn discs include visible scoring or lip formation on the friction surface, vibration through the steering wheel under braking, and a persistent grinding noise even with new pads fitted. Disc replacement is an intermediate DIY task; you will need a torque wrench, a breaker bar (some hub-to-disc retaining screws seize over time), and a jack with axle stands — budget 1–2 hours per axle. When selecting brake discs, check that the disc type (vented or solid) matches the original, and look for a protective anti-corrosion coating on the hub and non-friction surfaces to prevent rust jacking. Always replace discs in pairs (both sides of the same axle) to maintain even braking balance, and bed in new discs with the manufacturer's recommended gentle-braking procedure for the first 200 miles. Every part is dispatched with tracked delivery and a 14-day money-back guarantee with hassle-free returns.

TOPRAN, part of the Hans Thomsen Group headquartered in Hamburg, Germany, is a growing independent aftermarket brand focused on providing quality parts at accessible prices. TOPRAN offers a comprehensive range covering engine, cooling, electrical, braking, and body components for European vehicles. All TOPRAN products are manufactured to meet OE specifications and undergo quality testing before distribution. Combining German quality management with competitive pricing, TOPRAN is an excellent choice for cost-conscious motorists and workshops who do not want to compromise on part quality.