Raybestos Element3 power brake booster check valves restore braking performance. The brake booster check valve is essential for the proper functioning of your vehicle’s brakes. The valve prevents air from entering the braking system through the brake booster, which results in squishy brakes. Raybestos parts are vehicle specific and they meet factory specifications so they are easy to install without any modifications. Raybestos provides a limited warranty for non-conforming products.