On the MGA, all brake master cylinders, front drum brake slave cylinders, and disc brake calipers (front and rear for the Twin Cam and "Deluxe" cars) were cast iron. Rear drum brake slave cylinders and clutch slave cylinders were aluminum. Covers for the standard dual barrel master cylinders and the Twin Cam and "Deluxe" brake master cylinder were aluminum. MGA 1500, Twin Cam and "Deluxe" cars had zinc plated metal master cylinder screw caps, while the MGA 1600 had a white plastic (Nylon) screw cap.

None of these parts were originally painted. The zinc plated screw caps lose brightness in a few years and may go rusty in a few decades. Aluminum slave cylinders and master cylinder covers can lose a bit of luster with time but can be cleaned and polished if desired. The cast iron parts were always left to go naturally rusty, which is where the idea of paint comes in if you would like to have a finish prettier than rust. Some people may paint master cylinders black, and calipers might change to any color that strikes your fancy. For more original appearance you can paint any of these parts with clear coat (after very thorough cleaning). I have used satin finish clear lacquer on the master cylinder. It is not particularly durable, especially when dampened with Glycol based brake fluid (DOT 3, 4, or 5.1 type), which will soften most paints.

There is a special paint available for brake parts that is both chemical resistant and high temperature tolerant. This stuff is resistant to all current brake fluids and is good for 900dF (482dC). It is available in Gloss Clear, Cast Aluminum, Gloss black, Satin Black, and a few more primary colors. See VHT CALIPER PAINT at www.vhtpaint.com/products/caliperpaint.