Since I have at least one person's attention I'll continue to ramble about air brakes.
Let me play Murphy, I am uniquely qualified.
Scenario - someone less fortunate than the OP picked up 2 trucks and connected them via the appropriate towbars and chains and lights. He's driving back on I-10 during rush hour. There's a long steep hill on I 10 a little bit east of Fontana. Just as he reaches 65mph on the downhill side of the hill his compressor fails and his air pressure rapidly falls to zero. Traffic is at a standstill at the bottom of the hill.
Scenario 1 - before he left the GL yard he caged all the brakes on both trucks for no apparent reason. (Just to clarify, NOBODY is advocating this. Not me, not James, not anybody. This is just the worst case scenario. ). This doesn't end well. He stands on the brakes and nothing happens. Both trucks continue to accelerate downhill. Maybe he thinks to downshift and pull the park brake and maybe not. Doesn't much matter if he does or not. That one little cable brake isn't going to do much with a combined weight of 45,000 lbs or so. The trucks stop when he impacts something substantial, or perhaps he maneuvers sharp enough to overturn. Nothing good comes of this.
Scenario 2 - towed truck's brakes were caged prior to leaving the GL yard, but towing truck's brakes were not. Driver finds out about his loss of air when the spring brakes engage on the towing vehicle. The towed vehicle is unbraked. The combined 45,000 lbs is a lot to ask the towing truck's spring brakes to stop, especially downhill and already at 65mph. Stopping distances are greatly increased, resulting in impact. Or maybe we blow the locked up tires on the towing vehicle. This doesn't end well either. (I'd welcome further conjecture on how this one ends).
Scenario 3 - no cage bolt are in place prior to leaving GLs yard. Our driver becomes aware of his air loss when his springbrakes engage on both the towing and the towed vehicle. He's stopped in traffic and generally a nuisance to everyone around. Many people are making obscene gestures at him, and his vocabulary is greatly expanded , especially obscenities. Eventually CHP comes along and adds insult to injury by adding some tickets and an enormous tow bill. But everybody lives to tell the tale and this becomes a story he tells to convince others to have their MVs trailered for recovery....
