Air brake supply and service
Hi Jimmy and Hervy (spell your name right this time Hervy!)
Ryan here again with another question this time about the air brakes.
I'm trying to understand them to the best of my ability so I guess I explain what I think is happening in the air system and then you can correct me if I'm incorrect so I guess that will be my question - did i explain it correctly?
So the Service brakes gets compressed air from both the Primary Tank and the Secondary tank when you apply the brake pedal. The Secondary/Supply air tank is constantly giving air to the Spring Brake in order to "cage" the spring for both the tractor and trailer. When the air tank suffers air loss and the air gauge reads 60psi a warning light/buzzer will go off because the supply tank as lost too much air to compress the spring in the Spring Brakes. And the driver should pull over ASAP and when it is safe to do so.
So now with the two push/pull knobs inside the truck (this is where I'm confused, a bit). The yellow one is for? And the red one is for the trailer which looks like a stop sign in its shape. So is the Red knob just strictly for the trailer parking/Spring Brake and if so I don't really get what the Yellow knob is for 'cause doesn't that affect the trailer spring brakes too?
I hope you can help and explain it a bit better so that I can understand the air brake system.
P.S. I start my course tomorrow!!! I little nervous and excited at the same time!!! :)