Gladhands - service vs emergency

[liljohn]

So, what's the difference between the "service" and "emergency" gladhand hookups?

 

[rizzo]

one supplies air when you press the brakes, the other is always on (you have to manually turn it on with the valve) that unlocks the emergency brakes.

 

[Pinkie]

The service lines are Blue and the Emergency like is red. Now this is on all civvy road tractors, I do not know about MVs. I think all your questions will be answered by reading this.
http://www.tpub.com/content/engine/14081/css/14081_167.htm

Thanks,

J.R.

 

[rmgill]

More specifically, some military trailers work like trains. The air reservoir fills with air from the emergency line. The service brakes work normally pressurizing on the service glad hand when you step on the brakes and the diaphragm on the master cylinder actuating to engage the brakes on the trailer. If the trailer becomes unhooked accidentally, the emergency glad hand looses pressure on the trailer side and the loss of pressure throws a valve which dumps the pressure stored in the tank onto the diaphragm and engages the brakes for as long as the air pressure holds.

 

[liljohn]

Ok gotchya, thanks!