A clamp assembly for a mechanical leaf spring axle/suspension system of a heavy duty vehicle, the clamp assembly for securing at least one leaf spring (124; 140) of said mechanical leaf spring axle/suspension system to an axle thereof, wherein: said clamp assembly includes: an upper plate for disposal on an upper surface of said at least one leaf spring (124; 140); a top axle seat (160; 236) for disposal between a lower surface of said at least one leaf spring (124; 140) and an upper portion of said axle in general vertical alignment with said upper plate; a brake component mounting bracket (200; 234); the brake component mounting bracket (200; 234) including: a bottom axle seat for rigid connection to an axle of said vehicle, said bottom axle seat including a front portion and a rear portion and being configured to seat against a lower portion of said axle; an air chamber mounting bracket rigidly connected to said bottom axle seat for rigid attachment of a brake air chamber of a brake system thereto; and a cam shaft assembly mounting bracket rigidly connected to said bottom axle seat for rigid mounting of a cam shaft assembly of said brake system thereto; and at least one U-bolt for securing together said upper plate, said at least one leaf spring (124; 140), said top axle seat (160; 236), said axle, and said brake component mounting bracket (200; 234); characterized in that said brake component mounting bracket (200; 234) is formed with bosses that include openings for receiving respective ends of said at least one U-bolt; and the brake component mounting bracket (200; 234) for disposal on a lower portion of said axle such as to be in general vertical alignment with said upper plate and said top axle seat (160; 236). said clamp assembly includes: an upper plate for disposal on an upper surface of said at least one leaf spring (124; 140); a top axle seat (160; 236) for disposal between a lower surface of said at least one leaf spring (124; 140) and an upper portion of said axle in general vertical alignment with said upper plate; a brake component mounting bracket (200; 234); the brake component mounting bracket (200; 234) including: a bottom axle seat for rigid connection to an axle of said vehicle, said bottom axle seat including a front portion and a rear portion and being configured to seat against a lower portion of said axle; an air chamber mounting bracket rigidly connected to said bottom axle seat for rigid attachment of a brake air chamber of a brake system thereto; and a cam shaft assembly mounting bracket rigidly connected to said bottom axle seat for rigid mounting of a cam shaft assembly of said brake system thereto; and at least one U-bolt for securing together said upper plate, said at least one leaf spring (124; 140), said top axle seat (160; 236), said axle, and said brake component mounting bracket (200; 234); characterized in that an upper plate for disposal on an upper surface of said at least one leaf spring (124; 140); a top axle seat (160; 236) for disposal between a lower surface of said at least one leaf spring (124; 140) and an upper portion of said axle in general vertical alignment with said upper plate; a brake component mounting bracket (200; 234); the brake component mounting bracket (200; 234) including: a bottom axle seat for rigid connection to an axle of said vehicle, said bottom axle seat including a front portion and a rear portion and being configured to seat against a lower portion of said axle; an air chamber mounting bracket rigidly connected to said bottom axle seat for rigid attachment of a brake air chamber of a brake system thereto; and a cam shaft assembly mounting bracket rigidly connected to said bottom axle seat for rigid mounting of a cam shaft assembly of said brake system thereto; and a bottom axle seat for rigid connection to an axle of said vehicle, said bottom axle seat including a front portion and a rear portion and being configured to seat against a lower portion of said axle; an air chamber mounting bracket rigidly connected to said bottom axle seat for rigid attachment of a brake air chamber of a brake system thereto; and a cam shaft assembly mounting bracket rigidly connected to said bottom axle seat for rigid mounting of a cam shaft assembly of said brake system thereto; and at least one U-bolt for securing together said upper plate, said at least one leaf spring (124; 140), said top axle seat (160; 236), said axle, and said brake component mounting bracket (200; 234); characterized in that said brake component mounting bracket (200; 234) is formed with bosses that include openings for receiving respective ends of said at least one U-bolt; and the brake component mounting bracket (200; 234) for disposal on a lower portion of said axle such as to be in general vertical alignment with said upper plate and said top axle seat (160; 236).