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 scored, 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.
- Aluminum master cylinders may not be polished and must be replaced. On cast iron master cylinders, use crocus cloth to polish out light corrosion. Replace master cylinder if bore does not clean up using crocus cloth.
- 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.
CAUTION:
Do not install check valve in disc brake outlet, as this will cause disc brakes to lock up.