Mazda B3YD4380Z Brake Booster

1. Take off the upper engine cover by pulling it up from each side and lifting it off the mounting posts in the center. 2. Remove the nuts attaching the master cylinder to the booster and carefully pull the master cylinder forward until it clears the mounting studs, taking care not to bend or kink the brake lines. 3. For 2010 and later models, disconnect the brake lines from the brake pipe joint at the firewall that interfere with the booster, capping each end of the lines and pipe joint to prevent contamination. 4. Disconnect the vacuum hose from the power brake booster by depressing the tab and twisting it off. 5. Disconnect both cables from the battery and remove the battery. 6. Remove the PCM from the battery tray without disconnecting the electrical connectors, then take out the battery tray. 7. Under the instrument panel, remove the retaining pin and washer, then disconnect the pushrod from the top of the brake pedal. 8. Remove the fasteners attaching the booster to the firewall by taking off the four nuts, then carefully lift the booster unit away from the firewall and out of the engine compartment.