Which type of brake fluid is not compatible with DOT 3 fluid?

The correct answer reflects the fact that mineral oil-based fluids are not compatible with DOT 3 brake fluid. DOT 3 brake fluid is a glycol-ether based fluid, which has specific chemical properties that are required for optimal performance in conventional hydraulic brake systems. When brake fluid types are mixed, it can lead to various issues such as reduced boiling point, corrosion, and improper brake function, which can compromise safety.

Mineral oil-based fluids do not have the same chemical structure or performance characteristics as glycol-based fluids like DOT 3. As such, introducing a mineral oil into a system that uses DOT 3 can result in the formation of sludge and could damage seals and brake components that are designed to work with glycol-based fluids. This incompatibility makes it crucial to ensure that only recommended types of brake fluid are used for maintenance, particularly in systems designed for DOT 3 fluid.