Grand Cherokee 4WD V8-4.7L (2003)
Piston Seal
9. Remove piston seals from caliper and discard.
CAUTION: Do not scratch piston bore while removing the seals.
10. Remove caliper bleed screw.
Cleaning and Inspection
CLEANING - DISC BRAKE CALIPER
Clean the caliper components with clean brake fluid or brake clean only. Wipe the caliper and piston dry with lint free towels or use low pressure
compressed air.
CAUTION: Do not use gasoline, kerosene, paint thinner, or similar solvents. These products may leave a residue that could damage the piston and
seal.
INSPECTION - DISC BRAKE CALIPER
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.
Fig 14 Honing 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).
Assembly
ASSEMBLY - FRONT DISC BRAKE CALIPER
CAUTION: Dirt, oil, and solvents can damage caliper seals. Insure assembly area is clean and dry.
1. Lubricate caliper pistons, piston seals and piston bores with clean brake fluid.
