1999 Chevrolet Lumina - Bleeder Screw

What is a Brake Bleeder Screw?

The brake bleeder screw or bleeder valve is located on the back of your brake calipers or wheel cylinders, and is designed to allow air and old brake fluid to be purged from the brake system. When the brake bleeder valve is opened, it opens the system so the brakes can be bled. When the bleeder screw is closed, it seals the system and brake fluid to prevent leaks and allow the system to build pressure to activate the caliper or wheel cylinder. In some cases, bleeder screws may develop leaks or corrode over time. This can prevent them from seating properly, or may make it difficult or impossible to loosen the bleeder while attempting to bleed your brakes. Bleeder screws can also clog, prevent adequate fluid flow and make bleeding your brakes difficult. If your bleeder screw is damaged, corroded, or won't seal correctly, the bleeder screw can usually be replaced. However, if it's unable to be removed due to rust, then it's possible the entire brake caliper or wheel cylinder may need to be replaced. You can learn more about how to bleed brakes with our How-To resources, and if you need new bleeder screws, shop O'Reilly Auto Parts. We carry replacement brake bleeder screws, brake fluid, brake pads, and other brake repair parts to fit most vehicles.