Master Cylinder: Inspection
- Wash master cylinder body, bore and piston assemblies with denatured or isopropyl alcohol. Inspect piston assemblies and return springs. Replace pistons if they are scored galled, worn, cracked or broken. Replace springs if they are broken, bent, collapsed, distorted or fatigued.
- Inspect tube seat inserts in outlet ports. Replace if they are cracked, scored, loose, cocked or worn. If removal kits are not available, replace by using spiral easy-out.
- Remove check valve and spring from drum brake outlet (if equipped). Inspect cylinder bore for scoring, corrosion or wear. Aluminum master cylinders are anodized. Wear on the anodized surface, as evidenced by lighter areas, is normal.
- Use crocus cloth to polish out light corrosion on cast iron master cylinders. Replace master cylinder if bore does not clean up using crocus cloth. Aluminum master cylinders may not be polished and must be replaced.
- Inspect compensator and by-pass ports at bottom of reservoir. If they are plugged or dirty, clean them using brake cleaning solvent and compressed air only.