CLINTON, Mo. – Champion Brands, a global provider of specialty lubricants including brake fluid, is now offering to private label customers DOT 5 and DOT 5.1 brake fluid, in addition to traditional North American designations of automotive hydraulic brake fluids.
DOT 5 denotes a particular mixture of chemicals imparting specified ranges of boiling point. DOT 5 is a silicone-based brake fluid, which contains at least 70 percent by weight of a diorgano polysiloxane. Unlike polyethylene glycol-based fluids, it is hydrophobic. An advantage over other forms of brake fluid is that silicone has a more stable viscosity index over a wider temperature range. Another property is that it does not damage paint.
Using DOT 5 in a DOT 3 or DOT 4 system without proper flushing will cause damage to the seals and cause brake failure. DOT 5-brake fluid is not compatible with anti-lock brake systems, Champion warns.
DOT 5.1 is also one of several designations of automotive brake fluid conveying specified ranges of boiling point. A brake fluid’s dry boiling point is the temperature at which the pure fluid will boil. Wet boiling point concerns the boiling temperature when the fluid contains water. In the United States, all brake fluids must meet Standard No. 116 of the Federal Motor Vehicle Safety Standards (FMVSS).
Under this standard, there are three Department of Transportation (DOT) minimal specifications for brake fluid. They are DOT 3, DOT 4 and DOT 5.1 and all are polyethylene glycol-based fluids (contrasted with DOT 5, which is silicone-based). Polyethylene glycol fluids are hygroscopic and will absorb water from the atmosphere, which is necessary to prevent sheer and undiluted water in the braking system, which is very corrosive. Also, water droplets can freeze, thus blocking the system. DOT 5.1 is the non-silicone version of DOT 5, defined by FMVSS 116 as being less than 70 percent silicone.
