DOT 5 Brake Fluid
All brake fluids have necessary properties such as a high boiling and a low freezing point. They must not corrode or damage sensitive rubber components used throughout the automotive braking system. DOT 5 brake fluid is purple colored and contains silicon. Silicon brake fluid readily traps air and is not to be used with ABS systems. It's great when custom painted cars need the extra protection from paint damaging polyalkylene-glycol-ether (polyglycol) based fluids. DOT 3, 4, and 5.1 fluids are tan colored polyglycol fluids that are hygroscopic and attract and retain moisture. DOT 3 and DOT 4 fluids are far more common than DOT 5 fluids. Remember that these brake fluids are hygroscopic. It's important to keep the container capped tightly when in storage or they’ll become contaminated with moisture.