James, I realize you think I have no idea what I'm talking about. To the point that you've ignored what I've posted. I'm going to post this for the benefit of people reading this who are not familiar with air brake systems.
When the pressure in an airbrake system falls below a set minimum value, the spring brakes engage and the vehicle stops whether you want to or not. This makes it "fail safe".
When you install cage bolts in an air brake system, and then the air pressure falls to zero, the vehicle has no brakes at all (besides maybe a hand cable) and the vehicle continues until acted on by an outside force, frequently with catastrophic results. What you've done is make an inherently safe system a single point of failure.
I see people routinely install cage bolts anytime they tow an airbrake vehicle. Most of the time you'll get away with it, because the service brakes won't fail. All it takes is one failure though...one failed compressor and you have a potentially runaway truck.
When is the last time I removed a cage bolt that was apparently there for no reason whatsoever? Less than 2 weeks ago.....
I know you are tying to explain the workings of a working truck when we are driving it. The post thread he was going to tow his truck with another truck.
Yes that system is set up so if all else fails the spring brakes will stop the truck when the air pressure drops. Our safety net so to speak.
When we tow a truck that is a different story. Now as I have said we tow are trucks with our other military trucks. Is this correct? I am not going to say but it is being done. As I posted the big boys do cage if and when they feel it needs to be caged. If you read the link one driver likes to cage just because he feels there is a problem with the tow holding air so he cages all the cans so they do not engage while he is in tow even if the cans are good.
It would be up to you if you do not feel that you want to cage the bad cans and tow then call for a trailer as this will be cheaper than a large rotator wrecker.
If I was to decide to tow then I myself would cage the bad one and hope I don't loose another while in tow.
Just for a little more schooling when we go to get a military truck with air brakes this is what I think should be done. Do what ever you do to prepare for tow like pull axles/ drop drive line and transfer case in neutral. After hooking up the tow bar/ chains and light bar hook up the emergency air and air up the tanks. lesion for air leaks. Now release the spring brake and same thing lesion for air leaks anywhere plus all 4 cans real well. If one or more is leaking then we need to cage them and block off that air supply. As said before the best way is to remove the air line from the block and put a plug in it. If no air leaks are found then we go to the next step. Don't hook up the service air to the front of the tow. We know the emergency is holding but we need to check the service. With the tow charged and spring brakes released we are ready to tow pull the tow maybe 10 to 15 feet without the service air hook up just to see if she will roll ok. If so then we hook up the emergency air line from the tow truck to the tow service and this is like putting on the service brakes. Lession for air leaks in the service brake cans. Then try and pull the tow and the brakes should be locked up just like you hit the brake peddle in the tow. If it is locking up that is what we want to see so now we disconnect the emergency from the service line and put it back to where it should be emergency to emergency. Hook up service to service.
I still believe a military tow truck should be the best pick for towing a military truck. But sometimes we do what we do.
The good thing about the military trucks is we can supply service air and engage the brakes of the tow to help us stop. The civi trucks do not do this.Tthey can air up the tow to release the cans but just have a much larger truck to help with the stop.
I did not mean for this to be a pissing match just wanted to get the new boy informed as what he was looking at right now and what he might have to do to get the two trucks home.
The rest of the schooling he is just going to have to ask a lot of questions and read and drive.
Can we tow with the cans cage I feel like it can be done safe but as said without the right truck ,insurance, hook insurance, lights and such well I don't anymore and hope never to do it again. Make your own call but be careful.
As said never drive a truck with any cans caged only tow.
