I was having a discussion today, which led to the question
why do heavy trucks still use air brakes?
To my knowledge, it has been used for at least 40 years (I remember that as a kid), and apparently (I was told today but I haven't gotten around to verify it) they are still widely used.
From what I remember, one of the things I was cautioned was that if you repeatedly pressed on the air brakes, then after a while the air buffer would empty and it would take time to fill up (thus losing braking capacity).
Anyway, I wanted to know what are the benefits and disadvantages of air brakes compared to other technologies, e.g. hydraulic lines, or electrical system, (even KERS systems for more modern electrical vehicles).
UPDATE: From the answers I understand that the main issue is reliability and "technical debt". I want to push a bit further and understand, what's stopping air brakes from being used in other vehicles. E.g. is it cost, performance, inability to accompany AC/DC drum rhythm?