A little question for you all, i'm currently reading through the theory book about braking systems and air lines.. It states about a Red line, YELLOW line and Blue line..
Could you please explain what line does what and are they always the these colours or do they change?
I found out what the colours mean but a more in depth explanation would be a great help
Red - Emergency
Yellow - Service Line
Blue - Auxiliary
Thanks
Ignore colours!
You go by airlines and electrical suzies as they are called, you have two airlines, one (usually red tbh) is your primary feed, your trailer brake MUST be on before you connect it, people think air brakes use air pressure to apply the brakes, in actual fact, the air pressure is what releases the brakes , which is why you'll hear of a broken-down truck with its brakes locked on, if the air pressure is too low, it simply won't move.
You'll soon see its the fittings that matter, not the colours (the "suzies" on my Scania are all black!) basically each line will only fit in its corresponding connector so you simply can't attach them incorrectly.
Two electrical connectors, one powers everything, the other, known as an emergency, is, as it sounds, a backup.
You also have an ABS connector, if the trailer has a corresponding socket to fit it, it MUST be fitted by law, the chances - these days - of hitching up to a trailer without ABS is frankly zero, and tbh you would not want to tow a non-ABS equipped trailer either!
Have a watch of this, it explains it better than I could.
Colour wise, Red is your primary airline (if its coloured at all) yellow is its return line (the braking system being a circuit if you see what I mean)
A video I highly recommend to watch is this on reversing an artic, the guy is spot on.
