My buddy was working on the brakes of this truck this afternoon. He is almost sure he put silicone brake fluid in the system several years ago when we rebuilt his brake system. Silicone fluid is purple in the can but the fluid in his master cylinder is almost clear. The question is does silicone fluid lose it purple tint over time in a brake system? I would think it would remain purple in the system to keep from mixing DOT fluid with silicone fluid. Thanks

Six volt guy living in a twelve volt world