[mikestew]

That hasn’t been true in the U. S. for a good 50 years. Cars going back to the 60s had a small float switch that flipped a dashboard light if the fluid got low. As one who used to work on cars as a profession, I don’t recall that I’ve ever seen a car without this simple warning device.

The reason parent commenter doesn’t know this is because hydraulic leaks on auto brake systems are relatively rare as long as the vehicle darkens the door of a shop occasionally, even if rarely. Ergo, one might not even know there is a dash light.

[cardiffspaceman]

The lamp test, where all the lamps are turned on as the car starts, should be a sign that there is a lamp for this.

Or else how else would you know if the "brake" lamp still worked?

[mikestew]

Tell me with a straight face that you know more than one person beside yourself that actually looks at those lights at startup and checks that they are working. :-) I mean, you're right, but I'd venture to guess that for a lot of people the "lamp test" doesn't mean anything to them.

[cardiffspaceman]

I tend to think that this is one of those things that amateurs would only notice at first as, "I think that one of those red lights is not turning on at ignition." Not specifically the brake fluid level.