I mean it's common in air brakes used in commercial trucks as well. If air pressure is lost the brakes close: That's the failure condition. Done likely because

I mean it's common in air brakes used in commercial trucks as well. If air pressure is lost the brakes close: That's the failure condition. Done likely because these vehicles are larger and hydraulic brake fluid runs the risk of boiling (air compresses unlike fluid) and/or catching fire. As for brake fluid and fires, I had a neighbor's Ford Explorer (more like Exploder?) catch fire while parked and it burned down to the chassis due to this: https://www.cozen.com/admin/files/publications/Motor_Vehicle_Fires.pdf https://www.cozen.com/admin/files/publications/Motor_Vehicle...