U.S. & Metric Master Cylinder Plug Kit U.S. and Metric Master Cylinder Plug Kit, Part No. 803P, enables the technician to isolate the Master Cylinder from other brake components. It tests whether the internal seals are leaking or in good condition. Includes 26 machined aluminum plugs to fit most domestic and import vehicles. SAE sizes include: Two 3/8-24, two 7/16-24, two 9/16-18, two 9/16-20 and two 1/2-20. Metric sizes: Four M10x1.0, four M10x1.25, two M11x1.5, two M12x1.0, two M12x1.5 and two M13x1.5. Also included are thread gauge and instructions 803P Yes -