all right, lets see, parts of the Disc brake system. Starting from the wheel: Brake rotor, brake pads, Brake Caliper (parts inside consist of Brake Caliper Piston(s), Brake Caliper Piston Seal(s), Bleeder Screw, Banjo Bolt, Two (2) Copper Gaskets to seal brake line to caliper) Then you have the Brake Hose going to the frame (rubber, flexible, with fittings at each end). Attaching the Caliper to the Vehicle are Brake Caliper Guide Pins, which normally run through a set of bushings to help support and guide the caliper. Now jumping back to the lines. After your rubber line, you have a bendable, yet hard steel line that runs up to the Master Cylinder (assuming you're doing a vehicle without ABS). Inside the master cylinder, you have of course the Master Cylinder itself, its Reservoir (sp?), then you have a piston inside the Master Cylinder and its sealing washers/o-rings. At the back of the Master Cylinder, you have flange that bolts to the Power Brake Booster (again, assuming you have power brakes). Then you have the Booster, it consists of two metal buckets (essentially) crimped together, with a diaphragm (probably rubber) inside it. Attached to the outside of the booster is a plastic fitting that allows vacuum to be drawn from the engine. Attached to the Booster diaphragm there is a pushrod that leads to the back of the Brake Pedal. From there you've got the Brake pedal arm, which comes down to a foot at the bottom where you have your Brake Pedal Pad. I think that's about everything I can possibly think of. If I missed something, y'all let me know.