Brother T-8421A Sewing Machine Instruction Manual (Model 8421) - 57 Pages. Lost your sewing machine's manual? We've got you covered! This instruction manual is the ultimate guide to unlock the full potential of your Brother T-8421A. No more confusion or frustration—just clear, concise instructions right at your fingertips. What's inside? Everything you need to know from setting up to mastering your sewing machine and all its features.