When a brake pedal sinks straight to the floor without putting up a fight, the feeling can be unsettling — and that’s if you’re standing still. When a brake bleed doesn’t solve the problem and there are no obvious leaks along the brake lines or at the caliper, it’s time to consider replacing the master cylinder. Brake master cylinders have internal pressure regulators that can tear or fail over time, and though the task sounds daunting, replacing a faulty master cylinder really only takes a couple wrenches and an eye for detail.
Mechanical maven Scotty Kilmer is at it again in his latest video, which outlines the nuances of a successful brake master cylinder replacement. First, undo all of the brake lines from the master cylinder. Unbolt the master cylinder from the firewall, and gently tug until it comes free. Using an OEM replacement brake master cylinder from Pull-A-Part ensures proper fit. Bleed the brake system at the master cylinder, and at each wheel if necessary. Check for positive pedal pressure and you’re back on the road!
Source: Scotty Kilmer