Carlisle Brake & Friction's Logic Valves were developed to work with our standard and boosted master cylinders to provide additional brake system functions using integrated hydraulic logic functions. Logic valves are available as single and twin units and can be configured with “OR”, “AND” or “AND/OR” functionality to provide a pilot control signal to a front brake manifold, or a trailer brake valve, or to provide brake volume and pressure to a front brake circuit.