Failed my in-cab today. Can't figure out why...

Yeah you've just done the compulsory brake test explaining how you've pumped the brakes the warning light should come on at 75 psi and at 45 psi the emergency brake should kick in. now you've got to start it up and build the air pressure back up once the light goes out or in some cases the warning beeper stops beeping which is so annoying you should have enough to drive off however sounds like you've got one of those examiners that expects you to do everything by the book they would of been watching how much air pressure you had before you chose to drive off. Most drivers I mean experienced drivers would most likely fail the brake test because most do not wait until its built right up fact is you don't have to for the brakes to release, its like who really looks both ways when they go through a set of traffic lights on a green? Yet the examiner will expect you to do exactly that. I know cause they took points off my assessment for not doing so. Just make sure you do it exactly how the examiner wants it done and by the way your instructor should of explained this to you. Once you've passed i wouldn't worry to much about doing things that way, its just keeping the right people happy till your passed out.

 

Warning light or buzzer must come on before air pressure falls Below 60 psi. That's the requirement