Trailer Emergency Brake Incident

[Dr Dave]

It seems that some are projecting a trailer with full emergency brakes activated that is still attached to the tow vehicle is possible or likely to skid out of control. As the OP stated it smoked big time and he pulled over and determined what happened. No dangerous skid just locked up brakes. If a trailer is behind the tow vehicle and still attached and all 4 brakes lock up symmetrically ( which they should) the trailer will not skid out of control unless the tow vehicle locks up all it's brakes and steers violently to the side. The trailer becomes a dead weight with a lot of friction but should track straight as the tow vehicle brakes to a stop. The trailer tires will most likely be destroyed depending on speed at lockup but there should not be a transverse skid unless only one side brakes lock. Thus I do not see how you can compare the risk to not having the emergency cable connected. Matter of fact I see no risk at all. If you have not checked the status of the battery powering the system you might want to do so they do not last forever.

Years ago the trailer shop that help me with my first trailer with emergency brakes showed me how to take the cable thread it through a ring hole on the tow vehicle hitch and then return to a clip that could be attached to a link on the safety chain and thus could adjust the length as needed.
I have wondered about that but it seems a common practice and is normally on a link that is 2-3 from the trailer attach point. Since the cable would be pulled prior to chains going tight it seems ok. What do our two experts (Dr Dave and soundguy) think of that technique.

This would work if you or anybody hooking up had the cable about 3" shorter than the chain length. But can you be sure every time? I find it is best to cut the cable to the proper length. If there is not a good atachment point for the cable, you can install an eye bolt on the bumper. Good point about the battery, all our trailers have been fitted with a solar charger, and inspected twice a year.

Dave

 

[joshuabardwell]

I'd be careful with this idea as a couple raps around anything will just cinch on that item causing the cable to break long before it pulls the pin. Try it. On a slow pull, it may work but on a quick jerk, it will not.

I was thinking the same thing.

With regard to the cable being shorter than the chains, I still can't see how this could work. I have tried shortening up my cable using various methods, and whenever it gets short enough, I end up yanking it out on a tight turn. Maybe I should custom-cut it to length. But still, it leaves me wondering... if the trailer came off the ball and was hanging by the chains, I can basically guarantee you that the electrical connection to the truck would still be plugged in, so the regular brakes would work fine. It seems like the real purpose of the breakaway kit would be to stop the trailer in a total loss.

The other thought that I'll share is, I have heard of more than one case where a person's hitch broke off from their frame entirely. Granted, these cases are all where the person was overloading their hitch, but... I always hook my breakaway cable's clip to the hitch's safety chain receiver. But if the hitch were to come off entirely, the brakes wouldn't activate. It leaves me wondering whether it would be better to hook the safety cable to a part of the truck other than the hitch.

 

[Dr Dave]

Please give some idea of how to determine proper chain and cable lengths for the ones here who want advice from a person who knows the proper way.

Thanks

Hook up your trailer, the chains should hang about 4" to 6 " from the ground, like Chris said 3" shorter on the cable is good.

Many trailers come with under sized safty chains and S hooks. I use forged hooks with the safety latch, and chains rated higher than the max load.

Dave

 

[David_Kb7uns]

I read half these responses and could not read anymore, Most are wrong. I work on 3 to 5 trailers a week, for a living.

First off the trailer emergency brake is to activate the brakes if the trailer comes off the hitch ball or pintle hitch, the cable must be shorter than the chains.
Then the brakes are applied to slow the trailer for a controled stop, chains are ment to keep the trailer behind you. If the brakes are not applied, this could lead to possible chain failure, truck trailer damage, or worse. All trailer brakeaway switches, come with a long cable, they must be cut to length, and a snap hook should be installed, get the hook and the cable crimp type clamp from a hardware store, its easy to do.

The chains must be the proper length also, not dragging or twisted, they should be crossed at the tongue, to cradle tongue, if hitch comes unhooked, this prevent it from digging in and possibly breaking chains or worse. The chains and hooks should be heavy enough, not to break, many are not!

I would bet 75% of the trailers and pickups on the road are not properly set up, hooked up or maintained. Take 10 min. and go check yours, it could save a life.

Have a safe day

Dave

This may come down to regional preference as there is great debate over the break away cable being longer than the chains or shorter. The break away device that most laws cover is the total seperation of tow vehicle and trailer and must be able to stay locked for 15 minutes. Having a full application of brakes if a coupler comes off the ball may not be desired and measured application with a brake controller is better. Please show me the information that this is required as I still do not believe having the brakes totaly lock while chains are connected is required by law and it is only required if there is a total seperation. I know that having the brakes lock on my triple axle travel trailer would not be a good thing at all. You might hop on over to the Open Roads Forums and jump in the thread there as it is very large .

David Kb7uns

 

[David_Kb7uns]

Hook up your trailer, the chains should hang about 4" to 6 " from the ground, like Chris said 3" shorter on the cable is good.

Many trailers come with under sized safty chains and S hooks. I use forged hooks with the safety latch, and chains rated higher than the max load.

Dave

You guys better get on the trailer manufactures then because with the geometry of the safety chains at the end of the tongue and the break away switch being on the tongue back by the tongue jack on one side it is impossible to have the cable shorter then the chains with out ripping it out when turning the other direction, also some trailer makers are using one bar across the v of the tongue to attach the chains so you have one point of failure and crossing the chains does no good.


David Kb7uns

 

[JJZ 109]

I'd be careful with this idea as a couple raps around anything will just cinch on that item causing the cable to break long before it pulls the pin. Try it. On a slow pull, it may work but on a quick jerk, it will not.

Thanks for the heads up. Looks like the plan is to just make the cable the correct length. Fortunately, this particular trailer is always towed by the same vehicle.
I guess the wrap around way is kinda like tying a boat to a dock post. When the boat tugs on the rope, only that portion between the boat & the post take the tension. The remainder that hangs off the post just dangles and takes no load.
While I'm at it, I will most likely take Dr. Dave's advice and shorten the chains. Those things are twisted around each other about 3 times and still are only an inch or two from dragging.

Update:
After this post I made a trip the the hardware store for the stuff I needed. Chains and cable now should be the correct lengths.

 

[cqaigy2]

This has been an interesting thread. I want to add something i learned some years ago. I was picking up an empty trailer and looped the breakaway cable over the ball on the insert. Luckily a gentleman was standing nearby and ask me what would happen if my insert came out.

I have to admit i was alittle dumbfounded that i didn't see that for myself. I still see the same mistake being done and mention my story above.

 

[Dr Dave]

This may come down to regional preference as there is great debate over the break away cable being longer than the chains or shorter. The break away device that most laws cover is the total seperation of tow vehicle and trailer and must be able to stay locked for 15 minutes. Having a full application of brakes if a coupler comes off the ball may not be desired and measured application with a brake controller is better. Please show me the information that this is required as I still do not believe having the brakes totaly lock while chains are connected is required by law and it is only required if there is a total seperation. I know that having the brakes lock on my triple axle travel trailer would not be a good thing at all. You might hop on over to the Open Roads Forums and jump in the thread there as it is very large .

David Kb7uns

I have seen the results of many trailer disconnects, you do not want a total disconnect, most are totaled. When the chains hold and the breakaway does not function, do to improper install or a system that does not work, most end up jacknifed or upside down. And with a properly installed system, some road rash on chains and flat spot on tires. Which of the three would you want?

Dave

 

[Dr Dave]

This has been an interesting thread. I want to add something i learned some years ago. I was picking up an empty trailer and looped the breakaway cable over the ball on the insert. Luckily a gentleman was standing nearby and ask me what would happen if my insert came out.

I have to admit i was alittle dumbfounded that i didn't see that for myself. I still see the same mistake being done and mention my story above.

Good point, I seen this about 7 years ago, a guy from Canada puchased 2 Navy serplus engines from a ship yard, in the sothern US. He said he bought the new trailer for the trip, had a hitch installed on his truck, and went to Wallmart and bought a Rease insert and ball, he got the ball and insert with the hex and stamped indentation for the hex on the ball to fit in. On his way home he hit a large dip in I29, the insert split and ball came out, the breakawy cable was on the ball. Good thing for the chains. After looking at the receiver insert you could see 6 stress crackes at the corners of his new stamped insert, buyer beware.

Dave

 

[joshuabardwell]

I have seen the results of many trailer disconnects, you do not want a total disconnect, most are totaled. When the chains hold and the breakaway does not function, do to improper install or a system that does not work, most end up jacknifed or upside down. And with a properly installed system, some road rash on chains and flat spot on tires. Which of the three would you want?

I would really like to learn more about this. It seems like the trailer brakes would still function even if the trailer became decoupled, as long as the electric hookup to the vehicle was long enough. How does that hold up to reality?