Cherokee 2WD L6-4.0L VIN S (1998)
Brake Caliper: Testing and Inspection
The piston is made from a phenolic resin (plastic material) and should be smooth and clean.
The piston must be replaced if cracked or scored. Do not attempt to restore a scored piston surface by sanding or polishing.
CAUTION: If the caliper piston is replaced, install the same type of piston in the caliper. Never interchange phenolic resin and steel caliper pistons.
The pistons, seals, seal grooves, caliper bore and piston tolerances are different.
Polishing Piston Bore
The bore can be lightly polished with a brake hone to remove very minor surface imperfections. The caliper should be replaced if the bore is severely
corroded, rusted, scored, or if polishing would increase bore diameter more than 0.025 mm (0.001 inch).
