Brembo PS15 master-cylinder repair kit

NB: These instructions are given for guidance only and cannot engage the author's liability in the event of misinterpretation, failure to assess the vehicle's actual condition and/or non-conformity, unsuitable mechanical practice or the use of inappropriate tools.

Brembo PS15 master-cylinder repair kit. As always with brakes, the parts, tools and working environment must be absolutely clean.

Dismantling

  1. Remove the master cylinder and take off the lever.
  2. Clamp it moderately in a vice with soft jaws, brake-hose union facing up.
  3. With a pin punch, push the piston out downwards (one or two light hammer taps if needed — tap gently so as not to damage the hose-union thread). Collect all internal parts, including the spring's rubber stop. Do not throw away the old washers (useful for reassembly).
  4. Clean the bore with brake cleaner and inspect it: it must be perfectly smooth, free of scoring or corrosion.

Reassembly

Apply a little brake grease (supplied in the kit) to the new piston seals, and to the seals and washers. Insert the parts from inside to outside:

  1. Spring rubber stop
  2. Spring
  3. Piston with its seals
  4. Flat metal washer
  5. Rubber dust cover (shoulder facing inward)
  6. Preformed metal washer

Without a special tool, use the old washers and old dust cover to push the assembly into the master cylinder until the new washer and dust cover stay inside; then remove the old parts. Refit the lever after greasing its pivots and pin. Refit the master cylinder and its union, then bleed the brake system.