GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2009 🢒 Epica 🢒 Brakes 🢒 Hydraulic Brakes 🢒 Master Cylinder Overhaul

Disassembly Procedure

    Object Number: 1256224 Size: SH
  1. Remove the master cylinder. Refer to Master Cylinder Replacement.
  2. Remove the brake fluid reservoir. Refer to Master Cylinder Reservoir Replacement.
  3. Remove the screw from the cylinder.

    4. Object Number: 1256225 Size: SH

    Note: When removing the retaining ring, avoid damaging the piston or the cylinder wall.

  4. Remove and discard the retaining ring from the cylinder body by pressing the hollow shaft and using needle-nosed pliers to grasp and squeeze the retaining ring.

    5. Object Number: 1256226 Size: SH
  5. Remove the washer and the primary piston assembly.

    6. Object Number: 1256227 Size: SH
  6. Carefully remove the secondary piston assembly, including the spring, from the master cylinder bore.

Assembly Procedure

    Warning: Refer to Brake Fluid Warning in the Preface section.


    Object Number: 1256228 Size: SH

    Caution: Do not hone the master cylinder bore. When the brake master cylinder is overhauled, it is recommended that the cylinder body be replaced rather than CLEANED UP by honing the bore. The master cylinder has a hard, highly polished BEARINGIZED surface, which is produced by diamond boring followed by ball or roller burnishing under heavy pressure. Honing will destroy this hard smooth surface and cause rapid wear of the rubber cups.

    Note: Rubber parts and retaining rings must be discarded and replaced with new parts.

  1. Clean all the parts with denatured alcohol or clean brake fluid. Dry the parts with compressed air.
  2. Inspect the master cylinder bore for scoring or corrosion. If scoring or corrosion is evident, replace the master cylinder body.
  3. Lubricate the master cylinder bore with clean brake fluid.

    4. Object Number: 1256226 Size: SH
  4. Carefully insert the secondary piston assembly bore until the secondary piston contacts the base of the cylinder body. Use a wood or a plastic drift, if necessary.
  5. Insert the primary piston assembly and the washer.

    6. Object Number: 1256225 Size: SH

    Note: When installing the washer and the new retaining ring, take care not to damage the cylinder bore.

  6. Press the pistons into the cylinder bore using a wooden or a plastic drift.
  7. Insert the washer and the new retaining ring into the groove in the cylinder bore.

    8. Object Number: 1256224 Size: SH
  8. Install the retaining screw in the bottom of the master cylinder and tighten it until it bottoms out on the internal piston assembly.

    9. Object Number: 1256229 Size: SH
  9. Insert a new O-ring over the cylinder body.
  10. Install the brake fluid reservoir. Refer to Master Cylinder Reservoir Replacement.
  11. Install the master cylinder. Refer to Master Cylinder Replacement.
  12. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle.
  13. Bleed the brake system. Refer to Hydraulic Brake System Bleeding.
  14. Bleed the clutch master cylinder, if equipped. Refer to Hydraulic Clutch Bleeding.
  15. Lower the vehicle.