Master Cylinder: Disassembly
- Remove the brake master cylinder from the vehicle. See MASTER CYLINDER
under REMOVAL & INSTALLATION. Secure the mounting flange of the brake master cylinder in a bench vise so that the rear of the primary piston is accessible.
- Clean the outside of the master cylinder reservoir on and around the reservoir cap prior to removing the cap and diaphragm. Remove the reservoir cap and diaphragm from the reservoir.
- Inspect the reservoir cap and diaphragm for the following conditions:
- Cuts or cracks.
- Nicks or deformation.
If any of these conditions are present, replace the affected components.
- Remove the master cylinder reservoir from the master cylinder. See MASTER CYLINDER RESERVOIR
under REMOVAL & INSTALLATION. Using a smooth, round-ended tool, depress the primary piston and remove the piston retainer. Remove the primary piston assembly from the cylinder bore.
- Plug the cylinder inlet ports and the rear outlet port. Apply low pressure, non-lubricated, filtered air into the front outlet port, in order the remove the secondary piston (1) with the primary (6) and secondary (5) seals, and the return spring. See Fig 1
. Discard the primary piston assembly, the piston retainer, and the seals and seal retainer from the secondary piston.
Courtesy of GENERAL MOTORS CORP.