Proportioning valves are essentially pressure reducing valves and are oftenutilized in disc/drum, disc/disc and drum/drum braking systems. The valve is used to controlfront-to-rear brake pressure. Install this valve between the distribution block and the rear flex hose in the front-to rear rigid brake line. Always use tube wrenches to tighten fittings properly. Final settings of this valve will depend on your particular vehicle, and individual preference.