booster not a master cylinder how? would i know if the booster is going bad or gone bad and how would i be able to tell if it was actually my brake pads or my booster
the big round part is the booster, the reservoir in front of the booster that holds the brake fluid is the master cylinder, check all the brake pads and/or brake shoes, if they're all fine then bleed the system, if your not sure take it to a mechanic