GM 19209247
Master Cylinder

To replace the Brake Master Cylinder disconnect the electrical connector from the Brake Fluid Level Sensor and break pipes from the master cylinder ensuring that in the process you have installed a rubber cover/ plug on the ends of the exposed brake pipe fitting to prevent loss or contamination of brake tubes. Next plug the open brake end pipe ends, remove the master cylinder mounting nuts, and pull the master cylinder from the vehicle draining all the brake fluid from the reservoir. To install, bench the master cylinder above the vacuum Brake Booster, then install master cylinder mounting nuts, tightening to 25 nm (18 ft. Lbs.)). Unplug the brake pipes assembly, and attach it to the master cylinder, tighten the assembly to 15 nm (11 ft. Lbs). Finally, reconnect the electrical connector of the Brake Fluid Level Sensor and bleed the brake system.

Remove the master cylinder reservoir cap and diaphragm.

Bench bleed the new master cylinder before installing it to the vacuum brake booster.

Reattach the master cylinder reservoir and its cap and diaphragm before reinstalling the master cylinder to the vehicle.

Assemble the lubricated new primary seal and retainer, along with the new secondary seal onto the secondary piston, then install the lubricated return spring and secondary piston assembly into the cylinder bore, followed by the lubricated new primary piston assembly.

Bench bleed the master cylinder before installing it to the vacuum brake booster.