Brake Fluid Dye
 

Rather than resurrect the several year old thread I stumbled upon about the disappearance of ATE Super Blue, I thought I would post my common sense solution. Lots of hand-wringing over what sort of dye might be safe to put in your new brake fluid. Just dye the old stuff that you are going to flush and bleed until it shows up and then disappears. As long as the dye doesn't attack the components of the brake system for the 5 or 6 minutes it will be in the system, you should be golden. Or at least DOT amber.

Still worried about what is a safe dye? Suck some of the black stuff in your clutch master cylinder out and use it as your "dye" for the old brake fluid. You are gonna bleed it out right away, so...

I will now go back to sleep for another decade or so.

Good idea man. I was just bleeding my brakes with some new ATE 200 and was missing the old super blue, super hard to tell when I've gotten the line flushed with the new fluid so I usually end up doing extra which feels wasteful.

That's a cool thought as it gets flushed anyways. Food colouring powder would be my choice.

I was thinking about this also, but was thinking the liquid version.

I think the liquid is water-based, and you would not need any added moisture in your liquid ;)

Oh shit
Good point

Thanks
apparently the link still works.