Complete the installation by connecting the new brake lines to the master cylinder, installing the new vacuum hose for the brake booster, and bleeding the brake system. The brake booster needs a vacuum source from the engine to make it work. Master Power supplies a vacuum hose that's shortened to fit, as shown. It's a simple attachment to run the hose from the booster to a fitting on the intake manifold. If no fitting is in place, Master Power supplies one for installation on the manifold.