GM 19209249
Master Cylinder

Before you start working install the parking brake then disconnect the Brake Fluid Level Sensor power wire. Before starting work disconnect the brake pipes to protect brake fluid from leaking out or being contaminated. Take off the master cylinder nuts and remove the part before getting rid of the master cylinder reservoir. Start setup by inserting the master cylinder reservoir. Afterward prepare the master cylinder for bleeding. Mount the master cylinder onto the vehicle while adhering to fastener notices found in service precautions and tighten the mounting nuts to 36 n.m (27 lb ft). Join the brake pipes end to end and tighten their fittings to 25 n.m (18 lb ft). Reattach the Brake Fluid Level Sensor electrical connection and perform brake bleeding before let go of the parking brake.

Wrap the master cylinder with a clean shop cloth to prevent spills before finally removing it from the vise.

Install the master cylinder reservoir and bench bleed the master cylinder.

Remove the master cylinder mounting nuts and then the master cylinder itself, followed by the master cylinder reservoir.

Disconnect the brake pipes and plug them to prevent brake fluid loss or contamination.

Apply low pressure, non-lubricated, filtered air into the front outlet port.

Install the spring and spring retainer, followed by the primary seal and secondary seal on the secondary piston.

Remove the rubber cap or plug from the exposed brake pipe fitting ends.

Remove the pipe caps and connect the brake pipes, tightening the pipe fittings to 25 N.m (18 lb ft).

Use a smooth, round-ended tool to depress the primary piston and remove the piston retainer, followed by the primary piston assembly from the cylinder bore.

Remove the transparent hoses from the reservoir, reinstall the master cylinder reservoir cap and diaphragm, and then remove the fittings with the hoses from the ports.

Connect the brake pipes, tightening the fittings to 25 Nm (18 ft. lbs.).