In most cases, no, brake master cylinder components on a brake master cylinder are not replaced on a fixed schedule. They are generally replaced only when they show signs of wear or failure, such as a soft or sinking brake pedal, internal leaks, or contaminated brake fluid causing seal damage.
However, rubber seals inside the system can degrade over time, especially in older vehicles or if the brake fluid is not changed regularly. So while you don’t “regularly” replace it like oil or filters, it’s good practice to inspect the braking system during maintenance and replace components if symptoms appear or during a full brake system overhaul.
