2009 Chevrolet Trailblazer Brake Booster

First, you need to apply and release the brake pedal several times until the pedal becomes firm to deplete the power vacuum brake booster vacuum reserve, and use a suitable tool to remove the brake fluid from the Brake Master Cylinder reservoir. Then, please discard the brake fluid into an approved container and disconnect the master cylinder fluid level sensor electrical connector, the master cylinder secondary brake pipe fitting, and the master cylinder primary brake pipe fitting. Finally, you should remove the master cylinder nuts, the master cylinder and remove the O-ring seal from the master cylinder body.

First, you should ensure that the brake master cylinder reservoir is full to the maximum-fill level. If removal of the reservoir cap and diaphragm is necessary, you should clean the outside of the reservoir on and around the cap before removal. With the rear brake pipe installed securely to the master cylinder, you should loosen and separate the front brake pipe from the front port of the brake master cylinder. Then, please allow a small amount of brake fluid to gravity bleed from the open port of the master cylinder, reconnect the brake pipe to the master cylinder port and tighten securely. You also need to have an assistant slowly depress the brake pedal fully and maintain steady pressure on the pedal, loosen the same brake pipe to purge air from the open port of the master cylinder and tighten the brake pipe, then have the assistant slowly release the brake pedal. Finally, you should wait 15 seconds, then repeat the steps above until all air is purged from the same port of the master cylinder. With the front brake pipe installed securely to the master cylinder, after all, the air has been purged from the front port of the master cylinder, you should loosen and separate the rear brake pipe from the master cylinder, then repeat the steps above. After completing the final master cylinder port bleeding procedure, you should ensure that both of the brake pipe-to-master cylinder fittings are properly tightened.