Causes of MPU (Metal Sticking):

1. Uneven Pressure from the Caliper to the Pad:
   • The caliper applies uneven force to the brake pad.
   • This results in uneven pressure on the contact surface between the pad and the disc.
   • Leads to uneven wear, localized heat buildup, and increased risk of MPU.
2. Issues with the Ceramic Composition of Friction Material:
   • Ceramic pads generally have low thermal conductivity and reduced graphite (lubricant) content.
   • Improper formulation leads to concentrated heat on the friction surface.
   • Causes rapid carbonization of the binder (phenolic resin), preventing the formation of a lubricating transfer film.
   • High temperature and pressure conditions form hard spots, increasing the likelihood of MPU.
3. Entry of Solid Foreign Particles:
   • Hard contaminants may be introduced during production.
   • These particles cannot be removed during braking, causing MPU.
4. Brake Disc Material Composition:
   • Elements such as carbon (C) and silicon (Si) oxidize when scraped onto the friction surface under high temperatures.
   • These solid oxides exacerbate MPU formation.
5. Rust Accumulation:
   • Long-term parking may lead to heavy rusting of the brake disc.
   • Rust may be transferred to the brake pad or remain on the disc, leading to MPU and disc damage.
6. High Ferrite Content in Brake Discs:
   • Excessive ferrite content reduces the hardness of the disc.
   • This increases the chances of MPU during braking.

Recommended Measures:
✅ Inspect and diagnose the brake calipers for any faults. If any issues are found, repair or replace them based on the severity and nature of the damage.