Air and brake safety
Low Air and Brake Warnings Need a Direct Check
An audible leak, a low-air warning, slow pressure build, frequent compressor cycling, drag, pull, or a brake that will not release can involve different parts of the air and brake system.
Do not crawl under the truck or assume it is safe to drive from the warning alone. Tell dispatch whether the system builds and holds pressure, when the leak appears, whether the trailer is connected, and whether the unit has been placed out of service.