Is it legal to use compression fittings in auto brake lines?

No, it is generally not legal to use compression fittings in auto brake lines. Most automotive standards and regulations require the use of specific fittings and materials to ensure the integrity and safety of the braking system. Compression fittings can create weak points and may not withstand the high pressures typical in brake lines, leading to potential failures. Always consult local regulations and manufacturer guidelines for compliant brake line repairs.